Final answer:
Proteins are polymers made up of nitrogen-containing monomers called amino acids. They consist of a central carbon atom bonded to a hydrogen atom, an alkaline (basic) amino group NH2, an acidic carboxyl group COOH, and a variable group. Just 20 different amino acids contribute to nearly all of the thousands of different proteins important in human structure and function.
Step-by-step explanation:
Proteins are polymers made up of nitrogen-containing monomers called amino acids. An amino acid is a molecule composed of an amino group and a carboxyl group, together with a variable side chain. Just 20 different amino acids contribute to nearly all of the thousands of different proteins important in human structure and function. Body proteins contain a unique combination of a few dozen to a few hundred of these 20 amino acid monomers. All 20 of these amino acids share a similar structure. All consist of a central carbon atom to which the following are bonded: a hydrogen atom, an alkaline (basic) amino group NH2, an acidic carboxyl group COOH, and a variable group.