What type of chemical grouping present in all proteins?

Answer 1

A protein is any chain of amino acids. An amino acid is a small molecule that acts as the building block of any protein. If you ignore the fat, your body is about 20-percent protein by weight. It is about 60-percent water. Most of the rest of your body is composed of minerals (for example, calcium in your bones). Amino acids are called "amino acids" because they contain an amino group (NH2) and a carboxyl group (COOH) that is acidic. In the figure above, you can see the chemical structure of two of the amino acids. You can see that the top part of each one is the same. That is true of all amino acids -- the little chain at the bottom (the H or the CH3 in these two amino acids) is the only thing varying from one amino acid to the next. In some amino acids, the variable part can be quite large. The human body is constructed of 20 different amino acids (there are perhaps 100 different amino acids available in nature).