Amino Acids Study Guide

1) Amino acids are the basic building blocks of proteins (also called peptides and polypeptides).

2) There are 20 different amino acids that make up the proteins in the human body (and all other organisms).

The 20 Amino Acids

3) Amino acids have a common structure consisting of an amino group, a carboxyl group, a hydrogen atom and a side chain (R) around a central carbon atom.

The General Structure of an Amino Acid

4) Amino acids are mainly composed of carbon, hydrogen, oxygen and nitrogen.

5) Amino acids come in left-handed and right-handed versions. The kind found in biological proteins are left handed (or the L-sterioisomers).

6) The 20 amino acids are: glycine, alanine, valine, leucine, isoleucine, serine, thereonine, cysteine, methionine, proline, aspartic acid, asparagine, glutamic acid, glutamine, lysine, arginine, histidine, phenylalanine, tyrosine and tryptophan.