Amino acids are the building blocks of proteins. They contain an amino group, a carboxyl group, a hydrogen atom, and a variable side chain attached to the alpha carbon atom.
Amino acids exist as zwitterions in aqueous solutions, carrying both positive and negative charges. The isoelectric point is the pH at which the net charge is zero.
Amino acids are linked together by peptide bonds formed between the amino group of one amino acid and the carboxyl group of another, releasing a molecule of water.
Proteins are polymers of amino acids. They are essential for structural support, enzymatic activity, transport, and regulation of biological processes.