GLOSSARY

Peptide is a chain of amino-acid residues linked by peptide bonds. It may be a specific molecule or part of a digestion or hydrolysis mixture, without one effect applying to all types.

Dipeptides and tripeptides contain two and three amino-acid residues respectively. Boundaries among oligopeptide, polypeptide and protein vary by convention; length alone does not determine biological function. A hydrolysed mixture may also contain multiple chain lengths rather than one uniform molecule with a single predictable effect.

Common protein amino acids use amino and carboxyl groups in the chain backbone, while side chains create differences. Charge depends on the environment and pH; a neutral textbook drawing is not always the dominant bodily form. A chemical-group name alone establishes neither an ergogenic effect nor a supplement's nutritional value.