Peptide bụ ihe na-eme biochemical n'etiti amino acid na protein. O nwere arọ molekụla dị nta karịa protein, mana ibu molekụla buru ibu karịa amino acid. Ọ bụ iberibe protein. Nke ahụ bụ, site na ihe karịrị abụọ ma ọ bụ ruo ọtụtụ amino acid peptide bond polymerization n'ime peptide, wee site na otutu peptides nwere n'akụkụ ụdọ polymerization n'ime protein. Enweghị ike ịkpọ amino acid peptide, ga-abụrịrị ihe karịrị amino asịd abụọ jikọtara ya na njikọ peptide yinye a ga-akpọ peptide; Ọtụtụ amino acid agwakọtara ọnụ anaghị akpọ peptides; Amino acid ga-ejikọta ya na peptide bonds, na-akpụ "amino acid chain", "eriri amino acid", eriri amino acid nwere ike ịkpọ peptide. .