Protein = structural e.g. hair, bone...
Enzymes= Hormones, anitbodies...
Amino acids make up all proteins there are 20 essential amino acids and they make endless combos, all amino acids have the same
Protein = structural e.g. hair, bone...
Enzymes= Hormones, anitbodies...
Amino acids make up all proteins there are 20 essential amino acids and they make endless combos, all amino acids have the same basic structure:
- Carboxyl Groups
- Amine Groups
- R Groups
2 amino acids are bonded my a covalent peptide bond.
Lots of amino acids are polymerised to form a polypeptide.
All proteins have levels of structure:
Primary= which amino acids and in which order
Secondary- the shape the polypeptide takes (most common alpha helix)
Tertiary = how the secondary structures make themselves into a 3D shape (globular, fibrous)
I will now go into more detail...
This is the alpha helix, as you can see the R Groups will determine the structure of the helix (if they were large the coils would be bigger). Weak hydrogen bonds hold the coils in place. The ALPHA helix is folded or twisted to give the tertiary structure.
The beta pleated sheet is less common.
3D shape the poly peptide takes. Could be Fibrous protein- where the ALPHA helix coils into a long strand- this makes structural insoluble protein e.g. hair, collagen...
Most Tertiary structures are GLOBULAR this is when the helix is wound into a specific ball or globe shape. The shape is held into place by:
- Ionic bonds
- Sulphur bridges (in polypeptides where cystine is present)
Hydrophobic Rgroups twist the chain in on itself
Globular proteins specific to shape to carry out certian functions in the organism. E.G. and enzyme as an active site will only let a certain substrate fit.
At the Tertiary and Quaternary level of proteins some may CONJUGATE
These have an additional section which is a non-protein (the iron in Haemoglobin)
This is known as a prosthetic group.
They are normally essential to carry out certain functions.
4 polypeptides each with iron to make Haemoglobin, this allows the protein to carry 2 O2
whereas a single strand of the same protein is myoglobin that stores oxygen in muscles.
Testing for Protein
Animal protein= first class protein
Copper sulphate + Sodium Hydroxide
Purple is protein is present.
Enzymes- Globular Proteins
- Biological catalyst
- changes rate of reaction but doesn't get changed itself
- so it can get used over and over again
All reactions that occur in living organisms but would happen too slow with out Enzymes.
The enzymes reduce the activation energy so 