7.9B: The Relationship Between Genes and Proteins
Proteins, encoded by individual genes, orchestrate nearly every function of the cell.
LEARNING OBJECTIVES
Describe transcription and translation
Key Takeaways
Genes and Proteins
Since the rediscovery of Mendel’s work in 1900, the definition of the gene has progressed from an abstract unit of heredity to a tangible molecular entity capable of replication, transcription, translation, and mutation. Genes are composed of DNA and are linearly arranged on chromosomes. Some genes encode structural and regulatory RNAs. There is increasing evidence from research that profiles the transcriptome of cells (the complete set all RNA transcripts present in a cell) that these may be the largest classes of RNAs produced by eukaryotic cells, far outnumbering the protein-encoding messenger RNAs (mRNAs), but the 20,000 protein-encoding genes typically found in animal cells, and the 30,o00 protein-encoding genes typically found in plant cells, nonetheless have huge impacts on cellular functioning.
Protein-encoding genes specify the sequences of amino acids, which are the building blocks of proteins. In turn, proteins are responsible for orchestrating nearly every function of the cell. Both protein-encoding genes and the proteins that are their gene products are absolutely essential to life as we know it.
Replication, Transcription, and Translation are the three main processes used by all cells to maintain their genetic information and to convert the genetic information encoded in DNA into gene products, which are either RNAs or proteins, depending on the gene. In eukaryotic cells, or those cells that have a nucleus, replication and transcription take place within the nucleus while translation takes place outside of the nucleus in cytoplasm. In prokaryotic cells, or those cells that do not have a nucleus, all three processes occur in the cytoplasm.
Replication is the basis for biological inheritance. It copies a cell’s DNA. The enzyme DNA polymerase copies a single parental double-stranded DNA molecule into two daughter double-stranded DNA molecules. Transcription makes RNA from DNA. The enzyme RNA polymerase creates an RNA molecule that is complementary to a gene-encoding stretch of DNA. Translation makes protein from mRNA. The ribosome generates a polypeptide chain of amino acids using mRNA as a template. The polypeptide chain folds up to become a protein.
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Key Points
- Genes are composed of DNA arranged on chromosomes.
- Some genes encode structural or regulatory RNAs. Other genes encode proteins.
- Replication copies DNA; transcription uses DNA to make complementary RNAs; translation uses mRNAs to make proteins.
- In eukaryotic cells, replication and transcription take place within the nucleus while translation takes place in the cytoplasm.
- In prokaryotic cells, replication, transcription, and translation occur in the cytoplasm.
Key Terms
- DNA : a biopolymer of deoxyribonucleic acids (a type of nucleic acid) that has four different chemical groups, called bases: adenine, guanine, cytosine, and thymine
- messenger RNA : Messenger RNA (mRNA) is a molecule of RNA that encodes a chemical “blueprint” for a protein product.
- protein : any of numerous large, complex naturally-produced molecules composed of one or more long chains of amino acids, in which the amino acid groups are held together by peptide bonds


4.5: Problems Affecting the Family and How Children React to Stress
Types of Families
We have discussed throughout these modules that families can mean different things to different people. Support the patient’s view of who constitutes their family. Some children come from homes with a single-parent, while others may have parents who are divorced, or a parent who has died. Some children live in blended families where a parent has remarried. There may or may not be children from the new parent’s previous relationship or even new children from the new marriage. These adjustments may be difficult for the child to deal with. Divorce may be particularly difficult for children and they may express emotions such as anxiety, depression, sadness, and anger. Some children may even act out and have temper tantrums, start fights, and get into trouble in school. Home Health Aides/Personal Care Aides should provide support to the child by allowing them room to express their thoughts and feelings. If they have concerns about the adjustment of the child, these should be discussed with their supervisor. A social worker may be able to work with the child to assist them to adjust during stressful time periods of family change.
Guidelines for Communicating with Children about Divorce:
- Explain that the separation is not the child’s fault and that they are loved by both parents and the entire family.
- Ensure the child understands that they will still be taken care of by their parents and others who love them.
- Give the child room to express their thoughts and feelings. Some children may prefer to talk about and others to draw about their feelings.
- Encourage the family to maintain routines in the home and to keep rules and traditions as consistent as possible for the child.
- Encourage the parents to explain to the child reasons for the separation in a way they will understand.
Styles of Parenting
There are different styles of parenting. Diana Baumrind is a developmental psychologist who described four types of parenting styles:
- Authoritarian parenting : In this style of parenting, firm limits are placed on children and parents expect children to do as told without question (Santrock, 2009). Parents may spank the child, be threatening, and enforce rules without explaining why they are in place. A typical statement by an authoritarian parent may be, “Do it because I said so or else.” Children from these types of parents may be fearful, unhappy, and have poor communication skills (Santrock).
- Authoritative parenting : In this style of parenting, limits are placed on children but there is a verbal give and take between parent and child (Santrock, 2009). Children are encouraged to be independent within limits. Parents are nurturing and demonstrate warmth toward their children. A typical statement by an authoritative parent may be, “Let’s talk about why I want you to follow this rule.” Children from these types of parents often learn self-control, tend to be cooperative with others and positive (Santrock).
- Neglectful parenting : In this style of parenting, parents are uninvolved with the child (Santrock, 2009). The child is allowed to do whatever they want. A typical statement by a neglectful parent may be, “I don’t care. Do what you want. I am busy.” Children from these types of parents tend to have low self-esteem and may end up in risky situations in which they get into trouble (Santrock).
- Indulgent parenting : In this style of parenting, parents are very involved with their child but do not place enough limits on their children (Santrock, 2009). Children are allowed to do whatever they want, although the parent cares and is involved. A typical statement by an indulgent parent may be, “It’s okay. You can do what you want. I want you to be able to control your own life.” Children from these types of parents tend not to learn self-control and expect to get whatever they want (Santrock).
Authoritative parenting tends to be associated with the most positive outcomes for children (Santrock, 2009). If Home Health Aides/Personal Care Aides have concerns about parenting styles they see in the home, they should be discussed with their supervisor. She can help them develop a plan for educating parents about other ways to communicate with and set limits with children. Remember that there may be cultural differences in parenting. For example, Asian American parents tend to be authoritarian but in a less dominating way. Latino families also tend to use a more authoritarian approach but in a way that emphasizes respect and is not threatening. African American parents also tend to be more authoritarian and may use spanking. However, the use of physical punishment within this culture has been shown to have more positive outcomes within African American families (Santrock). While it is important to promote the most positive parenting style, it is also important to be aware of cultural differences and what may work best within one culture versus another.
1. Which of the following styles of parenting tends to be associated with the most positive outcomes for children?
a). authoritarian
b). authoritative
c). neglectful
d). indulgent
- Answer
-
1. B
Feedback :
1. Authoritative parenting, in which limits are placed on children but there is a verbal give and take between parent and child and children are encouraged to be independent within limits tends to be associated with the most positive outcomes for children.
Socioeconomic Status
Socioeconomic status means the social and financial level of the family. Families who have low incomes may have less access to resources than families from higher incomes. They may need more support from a HHA/PCA and more assistance to find resources available to them. It is important to ensure the family has access to resources such as food, clothing, and healthcare. There are resources within communities to help families who may be struggling. Federal and state financial assistance may also be available for these families. Home Health Aides/Personal Care Aides should discuss their concerns with their supervisor and how they can best help these families.
Children from low income families may struggle in school. They may feel embarrassed if their family is unable to afford the latest trends in clothing or technology. They may struggle with schoolwork and may not be getting the help they need at home. Share any concerns with a supervisor so that these issues may be addressed within the Care Plan.
Domestic Violence
Domestic violence is abuse that occurs by spouses, intimate partners, or family members. It can include any type of abuse such as physical abuse, emotional abuse, financial abuse, or sexual abuse. Domestic violence and the different types of abuse were discussed in Module Two.
Child neglect or maltreatment is when a child is harmed by a caregiver, (whether it is a family member or a healthcare worker), when the caregiver fails to provide necessary care. This includes failing to provide for the basic needs of a child such as food, shelter, and clothing. Neglect can mean abandoning the child, being inattentive to the child’s emotional needs, and neglecting the child’s education. For example, allowing a child to miss school so they do not get an adequate education is neglect. Neglect can be just as harmful as abuse . In fact, child neglect occurs more often than child abuse.
Children who come from homes where domestic violence occurs may have adjustment problems. They may suffer from anxiety, depression, have trouble forming positive relationships with others, have low self-esteem, and may get into trouble or engage in risky behaviors. Children who come from abusive homes are at risk for later becoming abusive themselves, particularly for sons. Daughters are more likely to end up in an abusive relationship themselves. Problems with alcohol and drug abuse, depression, and anxiety can also occur in later life.
If Home Health Aides/Personal Care Aides ever notice any signs of domestic violence, child abuse, or neglect, they should immediately report these to their supervisor. All health care workers are required by the law and have an ethical obligation to report incidents of child abuse. Refer to the agency’s policy on guidelines for reporting observed or suspected abuse to agencies, such as the local Child Protective Services. Laws may differ from state to state and country to country about how to report child abuse and neglect. Always follow your agency’s rules and state/country law for reporting suspected child abuse/neglect.
In families where domestic violence is actively occurring, the abusive person may likely need to be removed from the home. In some instances, the abused family members may need to enter a domestic violence shelter or be placed in a secure and confidential location, away from the abuser. Families where domestic violence occurs may benefit from parenting classes and in or out of the home counseling.
1. Which of the following would be signs of child abuse or neglect to report?
a). Unexplained bruises
b). Burn or teeth marks
c). Inadequate clothing for the weather (e.g. child has no coat in the winter)
d). Child is left home alone for two days
e).  The child reports to you their uncle touched them “down there”.
g). You notice long marks, some scabbing and some seem to be new on the child’s back when you bathe them
h).  You notice there is not enough food in the home and the children are often hungry
j). You discover a parent or caregiver is intoxicated and has driven a car with their children inside
- Answer
-
All answers are signs of abuse. If the HHA/PCA observes any of the above, they should immediately inform their supervisor and the appropriate authorities.
Special Issues of Families: Substance Abuse and Mental Health Issues
Some children may have parents that abuse alcohol or other substances or who have mental health illnesses. Substance abuse is a major factor in child abuse. According to the National Council on Child Abuse and Family Violence, more than 8 million children live with a parent who abuses substances, and between 40-80% of homes where there is substance abuse, there is also child abuse. The long-term effects of a parent abusing a substance on children include: depression, anxiety, an increased risk of the child eventually becoming a substance abuser, low self-esteem, and acting-out behaviors (National Council on Child Abuse and Family Violence).
Home Health Aides/Personal Care Aides may be the first to recognize that a parent is abusing a substance or has mental health issues. They should always report their observations to their supervisor and seek direction from them about what to do. They should also remember that if they ever feel unsafe in the home, leave immediately and call their supervisor.
Signs of Substance Abuse:
- An odor of alcohol on the breath
- The parent appears unkempt in appearance or the home is unkempt
- Children needs are not met and they may be neglected (e.g. no food, clothing, not going to school)
- The parent appears to be intoxicated (e.g. stumbling, slurring of words, abusive language)
- Blood shot eyes
- Shaky hands and irritability
- You find bottles or drugs hidden around the home
- The parent or caregiver seems forgetful, moody, or you observe sudden changes in behavior
- You notice the caregiver has insomnia or they report not sleeping for a couple of days
- You observe bizarre behaviors
- The children report they see their parent drink or use drugs
- The children seem afraid of the caregiver
Signs of Mental Illness:
- Children needs are not met and they may be neglected (e.g. no food, clothing, not going to school)
- You notice the caregiver has insomnia or they report not sleeping for a couple of days
- You observe bizarre behaviors
- The caregiver reports seeing or hearing things that are not there
- You notice the caregiver talking to themselves or what appears to be another person even though no one else is there
- The parent appears unkempt in appearance or the home is unkempt
- The children report strange behaviors of the parent
- You notice a change in behavior or mood
- You notice the parent seems withdrawn or apathetic (does not seem to care) about what is going on around them
- The children seem afraid of the caregiver
True or False?
1. Homes where substance abuse occurs also have higher rates of child abuse and neglect. True or False. ________
2. You should immediately report signs of substance abuse or mental health issues to your supervisor. True or False. ________
- Answer
-
1. True
2. True
Feedback :
1. Homes in which substance abuse occur also tend to have higher rates of child abuse and neglect. If the HHA/PCA suspects substance abuse or child abuse, they should immediately inform their supervisor.
2. If the HHA/PCA suspects substance abuse or child abuse, they should immediately inform their supervisor. It is important to protect the safety and well-being for children and to get the family the help that they need.
Stress
An important aspect of child development is to learn how to cope effectively with stress. Younger children are less able to understand stressful or traumatic events. They may think that they have caused the stressful event to happen. They may become unhappy, listless, not want to play as usual, forget to do homework, get poor test scores in school, or even become aggressive and act out, getting into trouble at home or in school. Older children and adolescents are better able to understand the causes of stress and to use cognitive coping skills to deal with the stressors in their lives. They too, however, may become anxious, depressed, and hopeless, make statements of wanting to hurt themselves or die, become aggressive, and get into trouble in the home or at school. Sometimes adolescents who have stress may engage in risky behaviors such as driving recklessly, engaging in unsafe sexual activity, or beginning to use drugs or alcohol.
How to Help Children Cope with Stress
- Provide reassurance that the child is safe and protected.
- Allow the child room to talk or draw about their thoughts and feelings.
- Reassure children that it is okay to feel stress, anxiety, or depression.
- Reassure children that traumatic events are not their fault.
- Protect children from stressful situations as much as possible and avoid discussing stressful or traumatic events in front of them.
- Correct any misconceptions about the stressful or traumatic event. Explain the situation in words the child understands.
- Teach children coping techniques to use when feeling stressed such as engaging in relaxing activities. These may include listening to music, dancing, coloring, and engaging in physical activities such as running and bike riding.
- For families that practice religious or spiritual beliefs, encourage children to turn to these practices in times of stress. Provide support and be respectful of these practices. Encourage children to talk to religious leaders.
- For older children and adolescents, talk to them about the cause of their stressors and help them plan ways to overcome the stressors. Children in these age groups are able to have a better understanding of stress and can think about how the future may be different without the stress. They are also able to think about what they could do to make changes to better deal with their stress. This helps to give them hope that things can change.


22.12B: Chemical Digestion of Carbohydrates, Proteins, Lipids, and Nucleic Acids
The chemical breakdown of the macromolecules contained in food is completed by various enzymes produced in the digestive system.
- Summarize chemical digestion
Key Points
- Protein digestion occurs in the stomach and the duodenum through the action of three main enzymes: pepsin, secreted by the stomach, and trypsin and chymotrypsin, secreted by the pancreas.
- During carbohydrate digestion the bonds between glucose molecules are broken by salivary and pancreatic amylase.
- The digestion of certain fats begins in the mouth, where short-chain lipids break down into diglycerides because of lingual lipase. The fat present in the small intestine stimulates the release of lipase from the pancreas, and bile from the liver enables the breakdown of fats into fatty acids.
- DNA and RNA are broken down into mononucleotides by the nucleases deoxyribonuclease and ribonuclease (DNase and RNase) that are released by the pancreas.
Key Terms
- zymogen : A proenzyme, or enzyme precursor, that requires a biochemical change (i.e., hydrolysis) to become an active form of the enzyme.
- lactose intolerance : The inability to fully metabolize lactose.
Chemical Digestion
Protein digestion occurs in the stomach and the duodenum through the action of three primary enzymes:
- Pepsin, secreted by the stomach.
- Trypsin, secreted by the pancreas.
- Chymotrypsin, secreted by the pancreas.
These enzymes break down food proteins into polypeptides that are then broken down by various exopeptidases and dipeptidases into amino acids. The digestive enzymes, however, are secreted mainly as their inactive precursors, the zymogens.
Thus, trypsin is secreted by the pancreas in the form of trypsinogen, which is activated in the duodenum by enterokinase to form trypsin. Trypsin then cleaves proteins into smaller polypeptides.
In humans, dietary starches are composed of glucose units arranged in long chains of polysaccharide called amylose. During digestion, the bonds between glucose molecules are broken by salivary and pancreatic amylase, and result in progressively smaller chains of glucose. This process produces the simple sugars glucose and maltose (two glucose molecules) that can be absorbed by the small intestine.
Sucrase is an enzyme that breaks down disaccharide sucrose, commonly known as table sugar, cane sugar, or beet sugar. Sucrose digestion yields the sugars fructose and glucose, which are readily absorbed by the small intestine.
Lactase is an enzyme that breaks down the disaccharide lactose into its component parts, glucose and galactose, that are absorbed by the small intestine. Approximately half the adult population produces only small amounts of lactase and are therefore unable to eat milk-based foods. This condition is commonly known as lactose intolerance.
The digestion of certain fats begins in the mouth, where lingual lipase breaks down short chain lipids into diglycerides. The presence of fat in the small intestine produces hormones that stimulate the release of pancreatic lipase from the pancreas, and bile from the liver, to enable the breakdown of fats into fatty acids. The complete digestion of one molecule of fat (a triglyceride) results in three fatty acid molecules and one glycerol molecule.
DNA and RNA are broken down into mononucleotides by the nucleases deoxyribonuclease and ribonuclease (DNase and RNase), which are released by the pancreas.
Carbohydrate digestion : A diagram of the action of the oligosaccharide-cleaving enzymes in the small intestine.
Lipid digestion : Lipid digestion involves the formation of micelles in the presence of bile salts, and the passage of micelles and fatty acids through the unstirred layer. The diagram depicts dietary fat at the top, with pancreatic lipase and bile salts forming micelles that will pass through the unstirred layer at the bottom of the diagram.


5.7: Summary
The topics covered in this chapter can be summarized as follows:
| Section | Summary |
|---|---|
| 5.1 Mechanical Weathering | Rocks weather when they are exposed to surface conditions, which in most case are quite different from those at which they formed. The main processes of mechanical weathering include exfoliation, freeze-thaw, salt crystallization, and the effects of plant growth. |
| 5.2 Chemical Weathering | Chemical weathering takes place when minerals within rocks are not stable in their existing environment. Some of the important chemical weathering processes are hydrolysis of silicate minerals to form clay minerals, oxidation of iron in silicate and other minerals to form iron oxide minerals, and dissolution of calcite. |
| 5.3 The Products of Weathering and Erosion | The main products of weathering and erosion are grains of quartz (because quartz is resistant to chemical weathering), clay minerals, iron oxide minerals, rock fragments, and a wide range of ions in solution. |
| 5.4 Weathering and the Formation of Soil | Soil is a mixture of fine mineral fragments (including quartz and clay minerals), organic matter, and empty spaces that may be partially filled with water. Soil formation is controlled by climate (especially temperature and humidity), the nature of the parent material, the slope (because soil can’t accumulate on steep slopes), and the amount of time available. Typical soils have layers called horizons which form because of differences in the conditions with depth. |
| 5.5 The Soils of Canada | Canada has a range of soil types related to our unique conditions. The main types of soil form in forested and grassland regions, but there are extensive wetlands in Canada that produce organic soils, and large areas where soil development is poor because of cold conditions. |
| 5.6 Weathering and Climate Change | The geological carbon cycle plays a critical role in balancing Earth’s climate. Carbon is released to the atmosphere during volcanic eruptions. Carbon is extracted from the atmosphere during weathering of silicate minerals and this is eventually stored in the ocean and in sediments. Atmospheric carbon is also transferred to organic matter and some of that is later stored in soil, permafrost, and rocks. Our use of geologically stored carbon (fossil fuels) has upset this balance and that has created a climate crisis. |
Answers to Review Questions at the end of each chapter can be found in Appendix 2 .
- What has to happen to a body of rock before exfoliation can take place?
- The climate of central B.C. is consistently cold in the winter and consistently warm in the summer. At what times of year would you expect frost wedging to be most effective?
- What are the likely products of the hydrolysis of the feldspar albite (NaAlSi 3 O 8 )?
- Oxidation weathering of the sulfide mineral pyrite (FeS 2 ) can lead to development of acid rock drainage (ARD). What are the environmental implications of ARD?
- Most sand deposits are dominated by quartz, with very little feldspar. Under what weathering and erosion conditions would you expect to find feldspar-rich sand?
- What ultimately happens to most of the clay that forms during the hydrolysis of silicate minerals?
- Why are the slope and the parent materials important factors in soil formation?
- Which soil constituents move downward to produce the B horizon of a soil?
- What are the main processes that lead to the erosion of soils in Canada?
- Where in Canada would you expect to find a chernozemic soil? What characteristics of this region produce this type of soil?
- Where are luvisolic soils found in B.C.?
- Why does weathering of silicate minerals, especially feldspar, lead to consumption of atmospheric carbon dioxide? What eventually happens to the carbon that is involved in that process?


16.4: The Ottonians
Ottonian Painting in the Early European Middle Ages
The Ottonian Renaissance (951-1024) was a period of cultural and artistic achievement inspired by the revival of the Holy Roman Empire.
Describe the painting of the Ottonian Renaissance
Key Points
- Originally a ducal family from Saxony, the Ottonians seized power after the collapse of Carolingian rule in Europe and re-established the Holy Roman Empire. This coincided with a period of significant church reform.
- Ottonian art reflects the Ottonians’ desire to confirm a holy Roman imperial lineage connecting them with the Roman emperors and their Carolingian predecessors. It fuses traditions and influences from late Roman, Byzantine , and Carolingian art.
- Ottonian ruler portraits are usually found in illuminated manuscripts and include motifs commonly found in ancient Roman iconography . Unlike classical art, however, these portraits lack a sense of naturalism , relying instead on iconography and hierarchical scale.
- Very few examples of wall painting from the Ottonian period survive. Those that have are in very poor condition or have been restored several times, often making it difficult or impossible to discover their correct dates of production.
Key Terms
- iconography : The branch of art history that deals with the symbolic value of an artwork’s subject matter and content.
- imperium : The right to command the force of the state; sovereignty.
Sculpture and Painting
Originally a ducal family from Saxony, the Ottonians (named after their first King Otto I the Great) seized power after the collapse of Carolingian rule in Europe and re-established the Holy Roman Empire. Ottonian rule was accompanied by renewed faith in the idea of imperium (Latin, roughly translated as “power to command”), referring to the sovereignty of state over individual). This coincided with a period of significant church reform. Both combined to create the Ottonian Renaissance (circa 951-1024), a period of heightened cultural and artistic fervor and achievement.
The Ottonian Dynasty desired to confirm a sacred Roman imperial lineage that connected them to the Christian rulers of Late Antiquity such as Theodoric and Justinian and to their Carolingian predecessors, particularly Charlemagne. Ottonian art reflected this desire, fusing traditions and influences from late Roman, Byzantine, and Carolingian art.
The style is generally grand and heavy, sometimes to excess, and initially less sophisticated than the Carolingian equivalents. Additionally, the Ottonian style exhibits no direct influence from Byzantine art and less understanding of its classical models. Surviving paintings from this period exist predominantly in illustrations from illuminated manuscripts and a small number of mural and fresco fragments. In fact, illuminated manuscripts are the best source of painted imperial portraiture from the Ottonian Renaissance.
Ruler Portraits
Ottonian ruler portraits usually combine ancient Roman elements with contemporary (medieval) ones. Portraits are most frequently found in the dedicatory prefaces of illuminated manuscripts. Ottonian art eschews naturalism for a more abstract style, focusing on symbolism to convey deeply philosophical and theological concepts.
A portrait of Otto II enthroned depicts the emperor wearing a bejeweled crown in lieu of a laurel wreath and a large disc bearing the cross in place of an imperial orb. However, his upright posture and general pose with one raised hand somewhat recalls the Colossus of Constantine , which sat in the Basilica Nova in the fourth century. Likewise, his attire slightly resembles a Roman toga, a sartorial mainstay among emperors and senators of ancient times. In a departure from classical art, however, Otto and the figures who flank him appear flat. Further, their scale is hierarchical, which organizes size in relation to importance. Otto is the largest of the five figures depicted. Lastly, the architectural space that surrounds the emperor fails to convey a sense of naturalistic recession into space.
Wall Paintings
Although it is clear from records that many churches were decorated with extensive wall painting, surviving examples are extremely rare, usually fragmentary, and in poor condition. As a result, their dates of production are uncertain, especially since many have been restored. Most surviving examples are clustered in south Germany, although there are also important examples from northern Italy. There is a record of bishop Gebhard of Constance hiring lay artists for a now-vanished cycle at his newly founded Petershausen Abbey (983). Laymen may have dominated the art of wall painting, perhaps basing their designs on monastic illuminations. The artists seem to have been nomadic, regularly moving throughout Europe.
The church of St. George at Oberzell on Reichenau Island has the best-known surviving example of wall paintings. However, much of the original work has been lost, and the remaining paintings to the sides of the nave have suffered from time and restoration. The largest scenes show the miracles of Christ in a style that shows both specific Byzantine elements and similarity with Reichenau manuscripts such as the Munich Gospels of Otto III . They are therefore usually dated around 980–1000. Indeed, the paintings are one of the foundations of the case for Reichenau Abbey as a major center of manuscript painting.
Ottonian Architecture in the Early European Middle Ages
Ottonian architecture flourished in the 10th and 11th centuries and drew inspiration from Carolingian and Byzantine architecture.
Compare and contrast Ottonian architecture with its Carolingian predecessor
Key Points
- Ottonian architecture first developed during the reign of Otto the Great (936-975) and lasted until the mid-11th century. Surviving examples of this style of architecture are found in Germany and Belgium.
- Ottonian architecture was inspired by Carolingian and Byzantine architecture and foreshadows Romanesque architecture in some features, including alternating columns and piers in regular patterns.
- Ottonian religious architecture diverges from the model of the central-plan church, drawing inspiration instead from the longitudinally oriented Roman basilica .
- The Ottonians adopted the Carolingian double-ended variation on the Roman basilica, featuring apses at both ends of the nave rather than just one. Churches make generous use of the round arch , have flat ceilings, and display the Ottonian appreciation of mathematical harmony by using modular planning.
Key Terms
- crypt : A stone chamber beneath the floor of a church or other building.
- crossing : The junction of the four arms of a cruciform church.
- ambulatory : The processional around the east end of a cathedral or large church and behind the high altar.
- apse : A semicircular projection from a building, especially the rounded east end of a church that contains the altar.
- capital : The uppermost part of a column.
- nave : The middle or body of a church, extending from the transepts to the principal entrances.
Originally a ducal family from Saxony, the Ottonians (named after their first king Otto I the Great) seized power after the collapse of Carolingian rule in Europe and re-established the Holy Roman Empire. Ottonian architecture first developed during the reign of Otto the Great (936 – 975 CE) and lasted until the mid-11th century. Surviving examples of this style of architecture are found today in Germany and Belgium.
Ottonian architecture chiefly drew its inspiration from Carolingian and Byzantine architecture and represents the absorption of classical Mediterranean and Christian architectural forms with Germanic styles. Some features foreshadow the development of Romanesque architecture, which emerged in the mid-11th century. Its balance and harmony are a remarkable reflection of the high regard in which the Ottonians held the mathematical sciences. This is evident in the modular planning, which bases the measurements of each component of the interior on a single square unit multiplied or divided accordingly.
Barring a few examples influenced by the octagonal Palatine Chapel built by Charlemagne in Aachen, Ottonian religious architecture tends to diverge from the model of the central-plan church, drawing inspiration instead from the Roman (Western) basilica. This typically consisted of a long central nave with an aisle at each side and an apse at one end. When adopted by early Christians, the basilica plan assumed a transept perpendicular to the nave, forming a cruciform shape to commemorate the Crucifixion.
The Ottonians adopted the Carolingian double-ended variation on the Roman basilica, featuring apses at the east and west ends of the church rather than just the east. Most Ottonian churches make generous use of the round arch, have flat ceilings, and insert massive rectangular piers between columns in regular patterns, as seen in St. Cyriakus at Gernrode and St. Michael’s at Hildesheim.
One of the finest surviving examples of Ottonian architecture is St. Cyriakus Church (960-965) in Gernrode, Germany. The central body of the church has a nave with two aisles flanked by two towers, characteristic of Carolingian architecture . However, it also displays novelties anticipating Romanesque architecture, including the alternation of pillars and columns (a common feature in later Saxon churches), semi-blind arcades in galleries on the nave, and column capitals decorated with stylized acanthus leaves and human heads.
St. Michael’s at Hildesheim (1010-1031) is one of the most important Ottonian churches, a double-choir basilica with two transepts and a square tower at each crossing . This layout can be seen from the exterior of the building. The west choir is emphasized by an ambulatory and a crypt . Adhering to the Ottonian appreciation for mathematics, the ground plan of the building follows a geometric concept in which the square of the transept crossing in the ground plan constitutes the key measuring unit for the entire church. The square units are defined by the alternation of columns and piers. Unlike St. Cyriakus, St. Michael’s lacks a second-story gallery. However, ample light enters through a row of clerestory windows placed above the arcades dividing the name from the aisles.
Ottonian Metalwork in the Early European Middle Ages
Ottonian metalwork ranged from jewel-encrusted objects of precious metals to large-scale bronze reliefs of stylized yet dramatic figures.
Discuss how Ottonian metalwork distinguished itself from Carolingian
metalwork
Key Points
- The Ottonians were renowned for their metalwork in precious and non-precious materials.
- Jeweled processional crosses embellished with portraits and engravings are some of the finest examples of Ottonian art and sculpture.
- The cover of the Codex Aureus of Echternach consists of an ivory plaque surrounded by gold repoussé reliefs produced in the elegant elongated style typical in Ottonian art.
- Ottonian metalwork use subject matter and iconography to refer to deep theological and philosophical concepts, as seen in the Bernward Doors and Bernward Column .
Key Terms
- iconography : Pertaining to the symbolic value of the subject matter or content of an artwork.
The Ottonians were renowned for their metalwork, producing bejeweled book covers and massive bronze church doors with relief carvings depicting biblical scenes, a process so complex that it would not be repeated until the Renaissance . Fine, small-scale metal sculpture flourished and exquisite book covers made of ivory and embellished with gems, enamels , crystals, and cameos were produced during this period.
The Cross of Lothair
Many of the finest examples of the crux gemmata (jeweled cross) date from Ottonian rule. These wooden crosses were encased in carved gold and silver and encrusted with jewels and engraved gems. Arguably the finest of these Ottonian jeweled crosses is the Cross of Lothair , dating from around 1,000 and housed in the Aachen Cathedral . The cross takes its name from the large engraved green rock crystal seal near its base , which bears the portrait and name of the Carolingian ruler Lothair II, King of Lotharingia (835-869). The cross was actually commissioned over a century later for Otto III, the Holy Roman Emperor . The cross bears a cameo of the great Roman emperor Augustus Caesar on one side and an engraving of the crucifixion of Jesus on the other. The cross thus represents both church and state in keeping with the Ottonian agenda, and connects the Ottonian emperors to the original Roman emperors.
The cross also depicts the Hand of God holding a wreath containing a dove representing the Holy Spirit in the crucifixion scene. This is the earliest-known appearance of the dove motif and the introduction of the entire Trinity into the crucifixion, iconography that has been repeated for centuries.
The Codex Aureus of Echternach
Ottonian relief figures from treasure bindings and cast sculptures are often more stylized yet more dramatic than their restrained Carolingian counterparts. The cover of the Codex Aureus of Echternach (1030-1050) dates from about 50 years before the manuscript. The metalwork is attributed to the Trier workshop set up by Egbert, Archbishop of Trier. It centers on an ivory plaque showing the Crucifixion. Surrounding the ivory plaque are panels with figures in repoussé gold relief. The style of the metal reliefs differ significantly from the central plaque. These panels are set in a framework with larger elements made up of alternating units of gold filigree set with gems and cloisonné enamel with stylized plant motifs. Thinner gold bands set with small pearls run along the diagonal axes, further separating the relief images into compartments and creating an “X” that may stand for “Christ.” The figures are produced in an elegant elongated style that contrasts strongly with the forceful and slightly squat figures of the ivory.
Bronze Sculptures in Hildesheim
Ottonian metalwork also includes objects produced from non-precious metals. The most famous of these is the pair of church doors, the Bernward Doors , commissioned by Bishop Bernward of Hildesheim. They contain biblical scenes from the Gospels and the Book of Genesis in bronze relief, each cast in a single piece. These powerfully simple compositions convey their meanings by emphatic gestures, a hallmark of the Ottonian style.
The figures on the Bernward Doors feature a progressive style of relief, leaning out from the background instead of extending a uniform distance. A particularly apt example of this is the figure of Mary with the baby Jesus in the depiction of the Adoration of the Magi. While her lower body is still in low relief, her upper body and Christ project out further and her head and shoulders are cast in the round . This unusual style was used for artistic reasons, not because of technical limitations.
Another striking Ottonian metal sculpture from is the Bernward Column (c. 1000), named for the same patron as the Bernward Doors . Produced for St. Michael’s Cathedral in Hildesheim, the column depicts images from the life of Jesus arranged in a helix similar to Trajan’s Column. Just as Roman victory columns depict the military deeds of the Emperor in an upward spiraling frieze , the Bernward Column depicts the peaceful deeds of Christ from his baptism at the Jordan to his triumphal entry into Jerusalem.
The column is significant for the vitality of the figural relief, which is unusual for its time. The relief complements the Bernward Doors . Both artworks reflect Bernward’s efforts to put his seat in the position of northern Rome in the context of the Ottonian Dynasty’s renewed Christian Roman Empire. They also emphasize Christ as a model of just and godly kingship for the rulers. For this reason, the execution of John the Baptist by Herod Antipas is given a great deal of space .
Ottonian Illustrated Books in the Early European Middle Ages
Ottonian monasteries produced lavish illuminated manuscripts under the sponsorship of emperors, bishops, and other wealthy patrons.
Describe the purpose and style of illustrated books in the Ottonian Renaissance
Key Points
- The illuminated manuscript is one in which text is supplemented by ornamentation in the form of colored initials, decorative borders, and miniature illustrations, sometimes executed with the addition of gold and silver leaf.
- Ottonian illuminated manuscripts were used for display and most commonly consisted of liturgical books , including psalters , gospel books, and huge complete Bibles.
- Manuscripts sometimes included a dedication portrait commemorating the book’s creation, in which the patron is usually depicted presenting the book to the chosen saint. Colored initials, borders, and marginalia also contain miniature portraits and other decorative emblems and motifs .
- Much Ottonian art reflected the dynasty’s desire to establish a visual link to the Christian rulers of Late Antiquity and their Carolingian predecessors.
- The Registrum Gregorii, the Codex Egberti , and the Pericopes of Henry II are among the most important illuminated manuscripts of the Ottonian Renaissance .
Key Terms
- psalter : The Book of Psalms, often applied to a book containing the Psalms separately printed.
- lectionary : A book or listing that contains a collection of scripture readings appointed for Christian or Judaic worship on a given day or occasion.
- liturgical book : A book published by the authority of a church containing the text and directions for the liturgy or customary public worship of its official religious services.
- scriptorium : A room in a monastery set aside for the copying, writing, or illuminating of manuscripts and records.
The Ottonian Renaissance (circa 951 – 1024 BCE) coincided with a period of reform and growth in the church, providing an impetus for the production of religious art .
The Illuminated Manuscript
One of the most important art forms of the period was the illuminated manuscript, one in which the text is supplemented by ornamentation in the form of colored initials, decorative borders, and miniature illustrations, sometimes with the addition of gold and silver leaf. Ottonian monasteries produced some of the most magnificent medieval illuminated manuscripts, working with the best equipment and talent under the direct sponsorship of emperors, bishops, and other wealthy patrons.
The manuscripts produced by Ottonian scriptoria (monastic centers for copying texts) provide invaluable documentation of contemporary, religious, and political customs as well as the stylistic preferences of the period. The most richly illuminated manuscripts were used for display and were most liturgical books, including psalters, gospel books, and large, complete Bibles. These lavish manuscripts sometimes include a dedication portrait commemorating the book’s creation in which the patron is usually depicted presenting the book to the chosen saint. Colored initials, borders, and marginalia also contain miniature portraits and other decorative emblems and motifs. Illuminated manuscripts were enclosed in ornate metal book covers decorated with gems and ivory carvings.
Presentation Portraits
Following late Carolingian styles , presentation portraits of the patrons of manuscripts are very prominent in Ottonian art. Much Ottonian art reflected the dynasty’s desire to establish a visual link to the Christian rulers of Late Antiquity such as Theodoric and Justinian as well as to their Carolingian predecessors, particularly Charlemagne. For example, Ottonian ruler portraits typically include elements with a long imperial history as iconography , such as province personifications, or representatives of the military and the Church flanking the emperor.
Famous Artists and Scriptoria
Among the greatest artists of the Ottonian period was the anonymous Master of the Registrum Gregorii, who worked chiefly in Trier in the 970s to 980s. He derived his title from the miniatures in the Registrum Gregorii (a collection of letters by Pope Gregory the Great) and the Codex Egberti , a famous gospel lectionary manuscript, both for Archbishop Egbert of Trier (circa 950-993). However, most of the 51 images in the Codex Egberti , which represented events in the life of Christ, were made by two monks in the Benedictine monastery on the island of Reichenau on Lake Constance. Reichenau housed a scriptorium and artists’ workshop that was one of the largest and most influential in Europe during the late 10th and early 11th centuries. It became famous for its style of gospel illustration in liturgical books. Other famous scriptoria of the Ottonian age were found at the monasteries of Corvey, Hildesheim, and Regensburg, and the cathedral cities of Trier and Cologne.
The Pericopes of Henry II (1002-1012) is a luxurious medieval illuminated manuscript made for Henry II, the last Ottonian Holy Roman Emperor . The manuscript is a product of the Liuthar Circle of illuminators, who worked in the monastery at Reichenau. The style of the Liuthar Group departs further from classical traditions. Its figures are flattened, stylized , and have exaggerated gestures. Backgrounds are often composed of bands of color with a symbolic rather than naturalistic rationale. As with depictions of Otto II and Otto III, figures’ scale is relative to importance, not based on reality. For example, the Annunciation to the Shepherds depicts the angel as the largest and thus most important figure, followed by humans and animals, as was the commonly accepted belief in Christendom at the time. Manuscripts from the Liuthar Group introduced the gold background to Western illumination, a characteristic that would remain common until the Italian Renaissance.
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1.1.6: Russell’s Paradox
Extensionality licenses the notation \(\Setabs{x}{\phi(x)}\) , for the set of \(x\) ’s such that \(\phi(x)\) . However, all that extensionality really licenses is the following thought. If there is a set whose members are all and only the \(\phi\) ’s, then there is only one such set. Otherwise put: having fixed some \(\phi\) , the set \(\Setabs{x}{\phi(x)}\) is unique, if it exists .
But this conditional is important! Crucially, not every property lends itself to comprehension . That is, some properties do not define sets. If they all did, then we would run into outright contradictions. The most famous example of this is Russell’s Paradox.
Sets may be elements of other sets—for instance, the power set of a set \(A\) is made up of sets. And so it makes sense to ask or investigate whether a set is an element of another set. Can a set be a member of itself? Nothing about the idea of a set seems to rule this out. For instance, if all sets form a collection of objects, one might think that they can be collected into a single set—the set of all sets. And it, being a set, would be an element of the set of all sets.
Russell’s Paradox arises when we consider the property of not having itself as an element, of being non-self-membered . What if we suppose that there is a set of all sets that do not have themselves as an element? Does \[R = \Setabs{x}{x \notin x}\nonumber\] exist? It turns out that we can prove that it does not.
There is no set \(R = \Setabs{x}{x \notin x}\) .
Proof. For reductio, suppose that \(R = \Setabs{x}{x \notin x}\) exists. Then \(R \in R\) iff \(R \notin R\) , since sets are extensional. But this is a contradicion. ◻
Let’s run through the proof that no set \(R\) of non-self-membered sets can exist more slowly. If \(R\) exists, it makes sense to ask if \(R \in R\) or not—it must be either \(\in R\) or \(\notin R\) . Suppose the former is true, i.e., \(R \in R\) . \(R\) was defined as the set of all sets that are not elements of themselves, and so if \(R \in R\) , then \(R\) does not have this defining property of \(R\) . But only sets that have this property are in \(R\) , hence, \(R\) cannot be an element of \(R\) , i.e., \(R \notin R\) . But \(R\) can’t both be and not be an element of \(R\) , so we have a contradiction.
Since the assumption that \(R \in R\) leads to a contradiction, we have \(R \notin R\) . But this also leads to a contradiction! For if \(R \notin R\) , it does have the defining property of \(R\) , and so would be an element of \(R\) just like all the other non-self-membered sets. And again, it can’t both not be and be an element of \(R\) .
How do we set up a set theory which avoids falling into Russell’s Paradox, i.e., which avoids making the inconsistent claim that \(R = \Setabs{x}{x \notin x}\) exists? Well, we would need to lay down axioms which give us very precise conditions for stating when sets exist (and when they don’t).
The set theory sketched in this chapter doesn’t do this. It’s genuinely naïve . It tells you only that sets obey extensionality and that, if you have some sets, you can form their union, intersection, etc. It is possible to develop set theory more rigorously than this.


Figure 1.13: Kindred Grey (2021). “Flow Around a Circular Cylinder.” CC BY 4.0 . Adapted from James F. Marchman (2004). CC BY 4.0 . Available from https://archive.org/details/1.13_20210804
Figure 1.14: Kindred Grey (2021). “Drag Coefficient Variation with Reynolds Number for a Sphere.” CC BY 4.0 . Adapted from James F. Marchman (2004). CC BY 4.0 . Available from https://archive.org/details/1.14_20210804
Figure 1.15: Kindred Grey (2021). “Definition of the Pitching Moment Sign.” CC BY 4.0 . Adapted from James F. Marchman (2004). CC BY 4.0 . Available from https://archive.org/details/1.15_20210804
Figure 1.16: Kindred Grey (2021). “Relationship Between Lift, Drag, and Free Stream Velocity.” CC BY 4.0 . Adapted from James F. Marchman (2004). CC BY 4.0 . Available from https://archive.org/details/1.16_20210804
Figure 1.17: Kindred Grey (2021). “Plots of Lift and Drag Coefficient Versus alpha, Showing Stall (a).” CC BY 4.0 . Adapted from James F. Marchman (2004). CC BY 4.0 . Available from https://archive.org/details/1.17_20210804
Figure 1.18: James F. Marchman (2004). “Type of Pressure Distribution.” CC BY 4.0 .
Figure 1.19: SDASM Archves (2013). “Boeing 247.” The Commons . Available from https://www.flickr.com/photos/sdasmarchives/11343397173/
Figure 1.20: Björn Strey (2009). “Douglas DC-2 (PH-AJU) in flight at the Bremen Airport Flugtag<PHONE_NUMBER>).” CC BY-SA 2.0 . Available from https://commons.wikimedia.org/wiki/File:Douglas_DC-2_(PH-AJU)_in_flight_at_the_Bremen_Airport_Flugtag_(3519224016).jpg
Figure 1.21: Kindred Grey (2021). “Typical Leading and Trailing Edge Flap Effects.” CC BY 4.0 . Adapted from James F. Marchman (2004). CC BY 4.0 . Available from https://archive.org/details/1.21_20210804
Figure 1.22: James F. Marchman (2004). “The Clark Y Airfoil Shape.” CC BY 4.0 .
Figure 1.23: Kindred Grey (2021). “General effects of wing sweep on transonic drag rise.” CC BY 4.0 . Adapted from James F. Marchman (2004). CC BY 4.0 . Available from https://archive.org/details/1.23_20210804
Figure 1.24: Kindred Grey (2021). “Other Effects of Wing Sweep (a).” CC BY 4.0 . Adapted from James F. Marchman (2004). CC BY 4.0 . Available from https://archive.org/details/1.24_20210804
Figure 1.25: Kindred Grey (2021). “Supercritical Airfoil Shape.” CC BY 4.0 . Adapted from James F. Marchman (2004). CC BY 4.0 . Available from https://archive.org/details/1.25_20210804
Figure 1.26: Kaboldy (2012). “Convair F-102 Delta Dagger.” CC BY-SA 3.0 . Available from https://commons.wikimedia.org/wiki/File:Convair_F-102_Delta_Dagger.svg
Figure 1.27: Kindred Grey (2021). “Ideal (2-D) and Real (3-D) Lift Distributions on a Wing.” CC BY 4.0 . Adapted from James F. Marchman (2004). CC BY 4.0 . Available from https://archive.org/details/1.27_20210804
Figure 1.28: James F. Marchman (2004). “High AR wing on left has less area affected by flow around tip and, thus, less lift loss than the lower AR wing on the right. (a).” CC BY 4.0 .
Figure 1.29: James F. Marchman (2004). “Trailing Vortices.” CC BY 4.0 .
Figure 1.30: Kindred Grey (2021). “The “slope” of the lift curve decreases as AR decreases.” CC BY 4.0 . Adapted from James F. Marchman (2004). CC BY 4.0 . Available from https://archive.org/details/1.30_20210804
Figure 1.31: Kindred Grey (2021). “Downwash and Induced Drag.” CC BY 4.0 . Adapted from James F. Marchman (2004). CC BY 4.0 . Available from https://archive.org/details/1.31_20210804
Figure 1.32: Kindred Grey (2021). “An Elliptical Lift Distribution.” CC BY 4.0 . Adapted from James F. Marchman (2004). CC BY 4.0 . Available from https://archive.org/details/1.32_20210804
Figure 1.33: Kindred Grey (2021). “The British ‘Spitfire’ Plane.” CC BY-SA 2.0 . Adapted from Falcon Photography (2019). “Spitfire Belly Fairing.” CC BY-SA 2.0 . Original available from https://www.flickr.com/photos/falcon_33/48712711406/in/photostream/ . Adapted available from https://archive.org/details/1.33_20210804
Figure 1.34: Kindred Grey (2021). “Often wings are twisted to keep the tip area from stalling when the inboard wing stalls, as well as to give a low induced drag lift distribution over the span.” CC BY 4.0 . Adapted from James F. Marchman (2004). CC BY 4.0 . Available from https://archive.org/details/1.34_20210804
<!– pb_fixme –><!– pb_fixme –>


5.9: Reaction Rate
Reaction Rates (Kinetics)
When a reaction releases energy, the chemical change is exothermic. Release of energy does not guarantee that the reaction will take place within a reasonable amount of time. A measure of how quickly products form, is called the reaction rate.
Reaction Energy Diagrams
Reaction energy diagrams summarize the important information about a reaction in a single graph. The y-axis represents the energy and the x-axis represents the reaction progress (time). The relative energies of the reactants and products are determined by the potential energy stored within the molecules as chemical bonds. For an exothermic reaction A, the products are lower in energy than the reactants resulting in a release of heat. For an endothermic reaction B, the products are higher in energy than the reactants requiring the constant addition of energy to keep the reaction going. The reactants must possess a minimum amount of energy for a reaction to occur. In a reaction energy diagram, the minimum energy is described as the “activation energy” (\(E_a'\)). Because the activation energy can be viewed as a barrier to a reaction, a larger activation energy indicates a slower the reaction rate and a smaller activation energy indicates a faster the reaction rate.
Reaction A Reaction B
Figure \(\PageIndex{1}\): Reaction A is exothermic, Reaction B is endothermic.
Catalysts are substances that speed up a reaction without being consumed or changed by the reaction. Because of these properties, catalysts can be added in small quantities to increase reaction rates. Catalysts increase reaction rates by decreasing the activation energy of a reaction. The transition state represents the reactants in the correct orientation with the minimum energy for a reaction to occur. The energy difference between the reactants and the transition state is the activation energy. The addition of a catalyst to Reaction C increases the reaction rate by decreasing the activation energy as shown below. Catalysts do not affect the ΔH of the reaction. Most chemical reactions that take place in living things are catalyzed by proteins called enzymes .
Reaction C
No Catalyst Reaction With Catalyst Reaction
Figure \(\PageIndex{2}\): Addition of a catalyst lowers the activation energy of the reaction and speeds up a chemical reaction.
Another way to alter the rate of a reaction is to change the temperature . The higher the temperature the faster the reaction. At higher temperatures the kinetic energy of the of the reactants are greater, collisions between reactants take place more frequently and with greater energy, so reactants are able to find their way over the activation barrier to form products.
The rate of the reaction can also be varied by changing the concentration of one or more reactants. Concentration refers to the amount of substance that is present in a mixture. A higher concentration of reactants can increase the rate of a reaction. The more crowded the reaction mixture is with reactants, the more likely is the collisions between reactant molecules.
-
Use the reaction diagrams from Figure 5.9.1 to answer the following questions.
- Label the ΔH and indicate whether it is positive or negative.
- What is activation energy?
- Overlay a second reaction energy curve for Reaction B when a catalyst is added.
- Predict which reaction occurs at a faster rate in figure 5.9.2.


46.0: Prelude to Ecosystems
In 1993, an interesting example of ecosystem dynamics occurred when a rare lung disease struck inhabitants of the southwestern United States. This disease had an alarming rate of fatalities, killing more than half of early patients, many of whom were Native Americans. These formerly healthy young adults died from complete respiratory failure. The disease was unknown, and the Centers for Disease Control (CDC), the United States government agency responsible for managing potential epidemics, was brought in to investigate. The scientists could have learned about the disease had they known to talk with the Navajo healers who lived in the area and who had observed the connection between rainfall and mice populations, thereby predicting the 1993 outbreak.
The cause of the disease, determined within a few weeks by the CDC investigators, was the hantavirus known as Sin Nombre , the virus with “no name.” With insights from traditional Navajo medicine, scientists were able to characterize the disease rapidly and institute effective health measures to prevent its spread. This example illustrates the importance of understanding the complexities of ecosystems and how they respond to changes in the environment.


3.7: Antimalarials
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- Ernstmeyer & Christman (Eds.)
- Chippewa Valley Technical College via OpenRN
Malaria is a prevalent protozoal disease impacting individuals across the world. According to the Centers for Disease Control, approximately 1,700 cases of malaria are diagnosed in the United States each year. [1]
Indications: Antimalarials are used for the prevention or treatment of malaria.
Mechanism of Action: Antimalarial agents work by targeting specific intracellular processes that impact cell development. [2]
Special Administration Considerations: Antimalarial medications may impact hearing and vision so patients should be monitored carefully for adverse effects. Additionally, antimalarial medications may cause GI upset, so patients should be instructed to take these medications with food.
Patient Teaching & Education: Patients should receive instruction to take medication as prescribed and adhere to the full prescription regimen. Patients should minimize additional exposure to mosquitoes using preventative means such as repellents, protective clothing, netting, etc. Patients on chloroquine therapy should also avoid alcohol. Chloroquine can be extremely toxic to children and should be safely stored and out of reach. Patients receiving antimalarial therapy may have increased sensitivity to light and should be counseled to wear protective glasses to prevent ocular damage. Treatment often requires sustained regimens of six months or greater so patients should be monitored carefully for adherence and compliance. [3]
Now let’s take a closer look at the medication grid on chloroquine in Table 3.16. [4]
| Subclass |
Prototype/
Generic |
Administration Considerations | Therapeutic Effects | Side/Adverse Effects |
|---|---|---|---|---|
| Antimalarials | chloroquine |
Check for allergies
Contraindicated in patients hypersensitive to drug and in those with retinal or visual field changes Use cautiously in patients with severe GI, neurologic, or blood disorders; hepatic disease or alcoholism; or G6PD deficiency or psoriasis Take with food to prevent GI upset In severe or resistant cases, artesunate IV may be prescribed |
Prevention of malaria or improvement of an acute attack of malaria
For malaria prevention, the CDC recommends that patients take drug for 4 weeks after leaving the area |
Changes in vision
Changes in hearing Monitor renal function closely Monitor patient for overdose, which can quickly lead to toxic symptoms: headache, drowsiness, visual disturbances, nausea and vomiting, cardiovascular collapse, shock, and convulsions |
Critical Thinking Activity 3.16a
Using the above grid information, consider the following clinical scenario question:
A nurse is providing medication teaching to a patient who is planning on visiting a country with high rates of malaria to do mission work. The patient states, “I’m glad I only have to take this medication for a week. The side effects sound horrific!” What is the nurse’s best response regarding the length of therapy?
Note: Answers to the Critical Thinking activities can be found in the “Answer Key” sections at the end of the book.
- Centers for Disease Control and Prevention . (2018, November 15). Choosing a drug to prevent malaria. https://www.cdc.gov/malaria/travelers/drugs.html ↵
- Achieng, A., Rawat, M., Ogutu, B., Guyah, B., Ong'echa, J.M., Perkins, D., & Kempaiah, P. (2017). Antimalarials: Molecular drug targets and mechanism of action. Current Topics in Medicinal Chemistry, 17 , 1-15. ↵
- uCentral from Unbound Medicine. https://www.unboundmedicine.com/ucentral ↵
- Daily Med, dailymed.nlm.nih.gov/dailymed/index.cfm, used for hyperlinked medications in this module. Retrieved June 27, 2019 ↵


13.7: Exercises
1. Consider the network diagram in Figure 13.14 . For each directed edge, the first number is the capacity and the second value is intended to give a flow \(ϕ\) in the network. However, the flow suggested is not valid
a. Identify the reason(s) \(ϕ\) is not valid.
b. Without changing any of the edge capacities, modify \(ϕ\) into a valid flow \(\hat{ϕ}\). Try to use as few modifications as possible.
2. Alice claims to have found a (valid) network flow of value 20 in the network shown in Figure 13.15 . Bob tells her that there's no way she's right, since no flow has value greater than 18. Who's right and why?
3. Find an augmenting path \(P\) with at least one backward edge for the flow \(ϕ\) in the network shown in Figure 13.16 . What is the value of \(δ\) for \(P\)? Carry out an update of \(ϕ\) using \(P\) to obtain a new flow \(\hat{ϕ}\). What is the value of \(\hat{ϕ}\)?
4. Prove Proposition 13.7 . You will need to verify that the flow conservation laws hold at each vertex along an augmenting path (other than \(S\) and \(T\)). There are four cases to consider depending on the forward/backward status of the two edges on the augmenting path that are incident with the vertex.
5. Find the capacity of the cut \((L,U)\) with
\(L=\{S,F,H,C,B,G,I\}\) and \(U=\{A,D,E,T\}\)
in the network shown in Figure 13.16 .
6. Find the capacity of the cut \((L,U)\) with
\(L=\{S,F,D,B,A\}\) and \(U=\{H,C,I,G,E,T\}\)
in the network shown in Figure 13.16 .
7. For each of the augmenting paths \(P_1, P_2, P_3\), and \(P_4\) in Example 13.8 , update the flow in Figure 13.2 . (Note that your solution to this exercise should consist of four network flows. Do not attempt to use the four paths in sequence to create one updated network flow.)
8. Continue running the Ford-Fulkerson labeling algorithm on the network flow in Figure 13.12 until the algorithm halts without labeling the sink. Find the value of the maximum flow as well as a cut of minimum capacity.
9. Use the Ford-Fulkerson labeling algorithm to find a maximum flow and a minimum cut in the network shown in Figure 13.17 by starting from the current flow shown there.
10. Figure 13.18 shows a network. Starting from the zero flow, i.e., the flow with \(ϕ(e)=0\) for every directed edge \(e\) in the network, use the Ford- Fulkerson labeling algorithm to find a maximum flow and a minimum cut in this network.
11. Consider a network in which the source S has precisely three neighbors: \(B, E\), and \(F\). Suppose also that \(c(S,B)=30, c(S,E)=20\), and \(c(S,F)=25\). You know that there is a flow \(ϕ\) on the network but you do not know how much flow is on any edge. You do know, however, that when the Ford-Fulkerson labeling algorithm is run on the network with current flow \(ϕ\), the first two vertices labeled are \(S\) with label \((∗,+,∞)\) and \(F\) with label \((S,+,15)\). Use this information to determine the value of the flow \(ϕ\) and explain how you do so.


27.4: Prostaglandins and Other Eicosanoids
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- Charles Ophardt, Steven Farmer, Dietmar Kennepohl, & Layne Morsch
- University of Illinois Springfield
Learning Objectives
After completing this section, you should be able to
- describe the general structure of the prostaglandins, and identify a prostaglandin from a given list of organic structures.
- identify at least two important biological functions of prostaglandins.
Key Terms
Make certain that you can define, and use in context, the key terms below.
- eicosanoid
- prostaglandin
Eicosanoids
The members of this group of structurally related natural hormones have an extraordinary range of biological effects. They can lower gastric secretions, stimulate uterine contractions, lower blood pressure, influence blood clotting and induce asthma-like allergic responses. Because their genesis in body tissues is tied to the metabolism of the essential fatty acid arachadonic acid (5,8,11,14-eicosatetraenoic acid) they are classified as eicosanoids . Many properties of the common drug aspirin result from its effect on the cascade of reactions associated with these hormones. Eicosanoids include prostaglandins, leukotrienes, and thromboxanes.
Eicosanoids are primarily named off the ring system present in the molecule prostaglandin (PG), thromboxane (TX), leukotriene (LT). Common substitution patterns on the ring system are indicated with a letter in the name. Also, the number of double bonds in the molecule is indicated with a subscript number.
Prostaglandin structures for PGA, PGD, PGE and PGF
Structures for prostaglandins PGG, PGH and PGI and thromboxanes TXA and TXB
Thus the molecule PGH 2 means that it has the prostaglandin ring system with a type H Substitution pattern. The subscript 2 indicated that the molecule contains two double bonds.
Prostaglandin PGH 2
Prostaglandins
Prostaglandins were first discovered and isolated from human semen in the 1930s by Ulf von Euler of Sweden. Thinking they had come from the prostate gland , he named them prostaglandins. It has since been determined that they exist and are synthesized in virtually every cell of the body. Prostaglandins, are like hormones in that they act as chemical messengers, but do not move to other sites, but work right within the cells where they are synthesized.
Prostaglandins are found in low concentrations distributed in a large number of organs, tissues, and body fluids of mammals. They exhibit a broad spectrum of physiological activity and are remarkably potent. Their precise biological role is not entirely clear, but they are known to induce strong contractions of smooth muscle tissue (lungs, uterus) and to lower blood pressure and sodium levels. Prostaglandins also have been implicated in the control of pituitary hormones released from the hypothalamus, and in the incidence of "pain" as a response to fever and inflammation. In fact, the analgesic property of aspirin possibly may result from the inhibition of prostaglandin biosynthesis
Prostaglandins are unsaturated carboxylic acids, consisting of of a 20 carbon skeleton that also contains a five member ring and are based upon prostanoic acid, which is a C20 fatty acid in which there is a cyclopentane ring formed by connecting the C8 and C12 positions.
They are biochemically synthesized from the fatty acid, arachidonic acid. The unique shape of the arachidonic acid caused by a series of cis double bonds helps to put it into position to make the five member ring of the prostaglandin.
Arachidonic acid
There are a variety of functional groups present in prostaglandin structures. The can have one, two, or three double bonds. On the five member ring there may also be double bonds, a ketone, or alcohol groups. Some typical structures are shown below.
Thromboxanes
Thromboxanes play roles in clot formation and named for their role in thrombosis. They are potent vasoconstrictors and facilitate platelet aggregation. They are synthesized in platelets, as well. The anti-clotting effects of aspirin have their roots in the inhibition of synthesis of PGH2, which is the precursor of the thromboxanes. The most common thromboxanes are A2 (Figure 2.217) and B2.
Thromboxane A2 2
Leukotrienes
Another group of eicosanoid compounds are the leukotrienes (Figure 2.219). Like prostaglandins, leukotrienes are made from arachidonic acid. The enzyme catalyzing their formation is a dioxygenase known as arachidonate 5-lipoxygenase. Leukotrienes are involved in regulating immune responses. They are found in leukocytes and other immunocompetent cells, such as neutrophils, monocytes, mast cells, eosinophils, and basophils. Leukotrienes are associated with production of histamines and prostaglandins, which act as mediators of inflammation. Leukotrienes also trigger contractions in the smooth muscles of the bronchioles. When overproduced, they may pay a role in asthma and allergic reactions. Some treatments for asthma aim at inhibiting production or action of leukotrienes.
Leukotriene A 4 (LTA 4 )
Eicosanoid Biosynthesis
The biosynthesis of eicosanoids begins with the reaction of arachidonic acid with \(\ce{O2}\) which can be catalyzed by two different cyclooxygenase enzymes (COX-1 & COX-2).
In nature, prostaglandins arise by an oxidative cyclization of poly-unsaturated twenty-carbon fatty acids, which begins with enantiospecific removal of the L-hydrogen atom of the prochiral methylene group at C-13 coupled with enantiospecific introduction of oxygen at the allylic C-15 position. Subsequent cyclization and termination by addition of a second molecule of oxygen leads to a 15-hydroperoxy bicyclic peroxide (PGG), that is reduced to a 15-hydroxy bicyclic peroxide (PGH). These intermediates, known as prostaglandin endoperoxides, have been isolated and shown to yield prostaglandins. Reduction of the peroxy bridge gives PGF, while disproportionation gives β-hydroxy ketones PGE and PGD. The carbons in prostaglandins are numbered one to twenty starting at the carboxyl carbon and following the numbering system of the biosynthetic precursor fatty acids.


14.3.3: Premiums
Premiums are the monthly costs of the health insurance plan, similar to a subscription for a streaming service for music or television shows. Typically these are set for a year at a time, and often insurance companies increase premiums in subsequent years to offset ongoing increases in healthcare costs. Premiums are paid by the employer, the insured, or shared by both, and are based on the number of people covered under the healthcare plan (i.e. whether a single person, their spouse and/or dependent children are covered). Premiums are not based on usage - so the premiums are the cost of the insurance regardless of how frequently the beneficiaries see the doctor or what their healthcare costs are. By collecting premiums, healthy people who visit the doctor less essentially cover the costs of sicker people who use healthcare more. If the insurance company has more healthy folks than sick folks paying premiums, then their financial risk is lower.


4.1: The Speed of Reactions
Skills to Develop
- Describe the effects of chemical nature, physical state, temperature, concentration, and catalysis on reaction rates
So far, we have considered many chemical reactions that can occur and described them using chemical equations and stoichiometry. In real situations, however, just as important as knowing whether a reaction can occur is knowing how fast it will occur - and how to control that speed. The speed of a reaction is given by the reaction rate , a measure of how fast reactants are consumed and products are formed. The study of reaction rates is known as chemical kinetics .
The central theory of kinetics is collision theory . The premise of this theory is simple: molecules have to collide to react. Therefore, the speed at which a reaction takes place depends on two main factors:
- The frequency of collisions: The more often molecules collide with each other, the faster the reaction proceeds.
- The energy of collisions: The more forcefully molecules collide with each other, the more likely they are to react, and the faster the reaction proceeds.
The rates at which reactants are consumed and products are formed during chemical reactions vary greatly. We can identify five factors that affect the rates of chemical reactions: the chemical nature of the reacting substances, the physical state of the reactants, the temperature of the reactants, the concentration of the reactants, and the presence of a catalyst.
The Chemical Nature of the Reacting Substances
The rate of a reaction depends on the chemical nature of the participating substances. Reactions that appear similar may have different rates under the same conditions, depending on the identity of the reactants. For example, when small pieces of the metals iron and sodium are exposed to air, the sodium reacts completely with air overnight, whereas the iron is barely affected. The active metals calcium and sodium both react with water to form hydrogen gas and a base. Yet calcium reacts at a moderate rate, whereas sodium reacts so rapidly that the reaction is almost explosive.
The Physical State of the Reactants
Reactions in phases that easily mix, such as gases and liquids, occur much faster than reactions between solids. The extent of mixing of the reactants influences the frequency of molecular collisions - if reactants are more thoroughly mixed, the molecules will collide more often and thus react faster. For this reason, many chemical reactions are carried out in solution, where the reactants can easily move around through the solvent. For the same reason, reactions that are stirred proceed faster than reactions that proceed by diffusion.
Except for substances in the gaseous state or in solution, reactions occur at the boundary, or interface, between two phases. Hence, the rate of a reaction between two phases depends to a great extent on the surface contact between them. This depends on the state of subdivision of the reactants. A finely divided solid has more surface area available for reaction than does one large piece of the same substance. Thus a liquid will react more rapidly with a finely divided solid than with a large piece of the same solid. For example, large pieces of iron react slowly with acids; finely divided iron reacts much more rapidly (Figure \(\PageIndex{1}\)). Large pieces of wood smolder, smaller pieces burn rapidly, and saw dust burns explosively.
Video \(\PageIndex{1}\) : The reaction of cesium with water in slow motion and a discussion of how the state of reactants and particle size affect reaction rates.
Temperature of the Reactants
Chemical reactions typically occur faster at higher temperatures. Food can spoil quickly when left on the kitchen counter. However, the lower temperature inside of a refrigerator slows that process so that the same food remains fresh for days. We use a burner or a hot plate in the laboratory to increase the speed of reactions that proceed slowly at ordinary temperatures. In many cases, an increase in temperature of only 10 °C will approximately double the rate of a reaction in a homogeneous system.
Again, the reason goes back to molecular collisions. Temperature corresponds to the average kinetic energy of the molecules. Molecules with greater kinetic energy will collide with each other not only more often, but also with more force, increasing the rate of their reaction.
Concentrations of the Reactants
The rates of many reactions depend on the concentrations of the reactants. Rates usually increase when the concentration of one or more of the reactants increases because molecular collisions become more frequent when more reactant molecules exist in the same space. For example, calcium carbonate (\(\mathrm{CaCO_3}\)) deteriorates as a result of its reaction with the pollutant sulfur dioxide. The rate of this reaction depends on the amount of sulfur dioxide in the air (Figure \(\PageIndex{2}\)). As an acidic oxide , sulfur dioxide combines with water vapor in the air to produce sulfurous acid in the following reaction:
\[\ce{SO}_{2(g)}+\ce{H_2O}_{(g)}⟶\ce{H_2SO}_{3(aq)} \label{12.3.1}\]
Calcium carbonate reacts with sulfurous acid as follows:
\[\ce{CaCO}_{3(s)}+\ce{H_2SO}_{3(aq)}⟶\ce{CaSO}_{3(aq)}+\ce{CO}_{2(g)}+\ce{H_2O}_{(l)} \label{12.3.2}\]
In a polluted atmosphere where the concentration of sulfur dioxide is high, calcium carbonate deteriorates more rapidly than in less polluted air. Similarly, phosphorus burns much more rapidly in an atmosphere of pure oxygen than in air, which is only about 20% oxygen.
Video \(\PageIndex{2}\) : Phosphorous burns rapidly in air, but it will burn even more rapidly if the concentration of oxygen in is higher.
The Presence of a Catalyst
Hydrogen peroxide solutions foam when poured onto an open wound because substances in the exposed tissues act as catalysts , increasing the rate of hydrogen peroxide’s decomposition. However, in the absence of these catalysts (for example, in the bottle in the medicine cabinet) complete decomposition can take months. A catalyst is a substance that increases the rate of a chemical reaction without itself being consumed by the reaction. A catalyst increases the reaction rate by providing an alternative pathway or mechanism for the reaction to follow. Catalysis will be discussed in greater detail later in this chapter as it relates to mechanisms of reactions.
Chemical reactions occur when molecules collide with each other and undergo a chemical transformation. Before physically performing a reaction in a laboratory, scientists can use molecular modeling simulations to predict how the parameters discussed earlier will influence the rate of a reaction. Use the PhET Reactions & Rates interactive to explore how temperature, concentration, and the nature of the reactants affect reaction rates.
Summary
The rate of a chemical reaction is affected by several parameters. Reactions involving two phases proceed more rapidly when there is greater surface area contact. If temperature or reactant concentration is increased, the rate of a given reaction generally increases as well. A catalyst can increase the rate of a reaction by providing an alternative pathway that causes the activation energy of the reaction to decrease.
Glossary
- reaction rate
- the speed at which reactants are consumed and products are formed in a chemical reaction
- kinetics
- the study of the rates of chemical reactions
- catalyst
- substance that increases the rate of a reaction without itself being consumed by the reaction
Contributors
-
Paul Flowers (University of North Carolina - Pembroke), Klaus Theopold (University of Delaware) and Richard Langley (Stephen F. Austin State University) with contributing authors. Textbook content produced by OpenStax College is licensed under a Creative Commons Attribution License 4.0 license. Download for free at<EMAIL_ADDRESS>).
- Anna M. Christianson, Bellarmine University


1.2: Game Matrices and Payoff Vectors
We need a way to describe the possible choices for the players and the outcomes of those choices. For now, we will stick with games that have only two players. We will call them Player 1 and Player 2.
1.2.1: Example—Matching Pennies
Suppose each player has two choices: Heads (H) or Tails (T). If they choose the same letter, then Player 1 wins \($1\) from Player 2. If they don't match, then Player 1 loses \($1\) to Player 2. We can represent all the possible outcomes of the game with a matrix .
Player 1's options will always correspond to the rows of the matrix, and Player 2's options will correspond to the columns. See Table \(1.2.1\).
| Table \(1.2.1\): A Game Matrix Showing the Strategies For Each Player | |||
|---|---|---|---|
| Player 2 | |||
| Head | Tail | ||
| Player 1 | Head | ||
| Tail |
A payoff is the amount a player receives for given outcome of the game.
Now we can fill in the matrix with each player's payoff. Since the payoffs to each player are different, we will use ordered pairs where the first number is Player 1's payoff and the second number is Player 2's payoff. The ordered pair is called the payoff vector . For example, if both players choose H, then Player 1's payoff is \($1\) and Player 2's payoff is \(-$1\) (since he loses to Player 1). Thus the payoff vector associated with the outcome H, H is \((1, -1)\text{.}\)
We fill in the matrix with the appropriate payoff vectors in Table \(1.2.2\).
| Table \(1.2.2\): A Game Matrix Showing the Payoff Vectors | |||
|---|---|---|---|
| Player 2 | |||
| Head | Tail | ||
| Player 1 | Head | \((1, -1)\) | \((-1, 1)\) |
| Tail | \((-1, 1)\) | \((1, -1)\) |
It is useful to think about different ways to quantify winning and losing. What are some possible measures of value? For example, we could use money, chips, counters, votes, points, amount of cake, etc.
Remember, a player always prefers to win the MOST points (money, chips, votes, cake), not just more than her opponent. If you want to study a game where players simply win or lose (such as Tic Tac Toe), we could just use “\(1\)” for a win and “\(-1\)” for a loss.
1.2.2: Understanding the Players
Recall that we said there are two major assumptions we must make about our players:
- Our players are self-interested . This means they will always prefer the largest possible payoff. They will choose a strategy which maximizes their payoff.
- Our players are perfectly logical . This means they will use all the information available and make the wisest choice for themselves.
It is important to note that each player also knows that his or her opponent is also self-interested and perfectly logical!
- Which payoff does the player prefer: \(0\), \(2\), or \(-2\)?
- Which payoff does the player prefer: \(-2\), \(-5\), or \(-10\)?
- Which payoff does the player prefer: \(-1\), \(-3\), or \(0\)?
It may be straightforward to decide the best payoff for a player out of a list of values, and it would be great if a player could just determine the biggest value in the table and choose that strategy. However, when there are two players a player may have to choose a strategy more carefully, since Player 1 can only choose the row, and Player 2 can only choose the column. Thus, the outcome of the game depends on BOTH players.
Suppose two players are playing a game in which they can choose A or B with the payoffs given in the game matrix in Table \(1.2.3\).
| Table \(1.2.3\): Payoff Matrix For Exercise \(1.2.2\) | |||
|---|---|---|---|
| Player 2 | |||
| A | B | ||
| Player 1 | A | \((100, -100)\) | \((-10, 10)\) |
| B | \((0, 0)\) | \((-1, 11)\) |
In the following exercise, we will try to determine what each player should do.
- Just by quickly looking at the matrix, which player appears to be able to win more than the other player? Does one player seem to have an advantage? Explain.
- Determine what each player should do. Explain your answer.
- Compare your answer in (b) to your answer in (a). Did the player you suggested in (a) actually win more than the other player?
- According to your answer in (b), does Player 1 end up with the largest possible payoff (for Player 1) in the matrix?
- According to your answer in (b), does Player 2 end up with the largest possible payoff (for Player 2) in the matrix?
- Do you still think a player has an advantage in this game? Is it the same answer as in (a)?
Suppose there are two players with the game matrix given in Table \(1.2.4\).
| Table \(1.2.4\): Payoff Matrix For Exercise \(1.2.3\) | ||||
|---|---|---|---|---|
| Player 2 | ||||
| X | Y | Z | ||
| Player 1 | A | \((1000, -1000)\) | \((-5, 5)\) | \((-15,15)\) |
| B | \((200, -200)\) | \((0, 0)\) | \((-5,5)\) | |
| C | \((500, -500)\) | \((20, -20)\) | \((-25,25)\) |
In the following exercise, we will try to determine what each player should do.
- Just by quickly looking at the matrix, which player appears to be able to win more than the other player? Does one player seem to have an advantage? Explain.
- Determine what each player should do. Explain your answer.
- Compare your answer in (b) to your answer in (a). Did the player you suggested in (a) actually win more than the other player?
- According to your answer in (b), does Player 1 end up with the largest possible payoff (for Player 1) in the matrix?
- According to your answer in (b), does Player 2 end up with the largest possible payoff (for Player 2) in the matrix?
- Do you still think a player has an advantage in this game? Is it the same answer as in (a)?
This chapter has introduced you to who the players are and how to organize strategies and payoffs into a matrix. In the next chapter we will study some methods for how a player can determine his or her best strategy.