Molecules of Life

How many amino acids are found in humans?

There are twenty amino acids commonly found in humans. They are classified into four groups based on the identity of their side chain. The four groups are polar, nonpolar, acidic, and basic. These twenty amino acids are what make up all of the proteins and enzymes in your body. The interactions between the individual amino acids determine the overall conformation of the protein, though the relationship between the sequence of amino acids and the structure adopted by the protein is very difficult to predict.

