Amino acids

Amino acids are the building blocks of proteins. There are 20 naturally occurring amino acids. Amino acids exist in proteins as L-optical isomers, however they can extist as D-isomers in isolated examples. E.g. some bacterial cell walls contain D-isomers.

Amino acids can also be characterized as polar or non-polar, these dictate the amino acid function. There are 10 non-polar amino acids, these are found in protein core. There are also 10 polar amino acids, these have enzymatic roles, they can be used to bind DNA, metals and other naturally occuring ligands.