Proteins are probably the most versatile of all the organic molecules, making up many structures and executing various functions within organisms. Building blocks called amino acids make up proteins. About 20 different amino acids combine to form all of the various types of proteins on Earth. These amino acids all have almost the exact same composition; the only difference is the R group, which differs in each of the amino acids and gives them their uniqueness.
duration - the period of time during which something continues. continuance. period, period of time, time period - an amount of time; a time period of 30 years; hastened the period of time of his recovery; Picasso's blue period. clocking - the time taken to traverse a measured course; it was a world record clocking.
About Irregular Periods and Pregnancy. A regular period is defined as a 25  31 day cycle from the start of one period to the next, with three to five days of bleeding. Irregular periods are considered anything that diverges from the regular menstrual cycle.bout Irregular Periods and Pregnancy. A regular period is defined as a 25  31 day cycle from the start of one period to the next, with three to five days of bleeding. Irregular periods are considered anything that diverges from the regular menstrual cycle.