peptida

Peptida is a term used in several Romance languages to denote a peptide, a short chain of amino acids linked by peptide bonds. In English, the corresponding term is peptide, and the combining form peptid- appears in numerous scientific words such as peptidyl and peptidation.

A peptide consists of amino acids joined by one or more peptide bonds, forming a polymer that is shorter than a typical protein. Dipeptides and tripeptides contain two or three amino acids; oligopeptides are generally longer but still shorter than proteins, often up to about 20–30 residues, while longer chains are usually called polypeptides or proteins depending on their structure and function.

In biological systems, peptides arise from ribosomal translation of mRNA and, in many organisms, from non-ribosomal peptide synthetases. They can serve diverse roles, including hormones (such as insulin fragments), neurotransmitters, antimicrobial agents, and signaling molecules. Peptida-related terminology also covers post-translational modifications that enhance stability, activity, or specificity.

Chemically, peptides are synthesized in the laboratory by methods such as solid-phase peptide synthesis and can be analyzed by mass spectrometry and chromatographic techniques. Their study is fundamental in biochemistry, pharmacology, and medicine, where synthetic and naturally occurring peptides are explored as therapeutics, research tools, and biomarkers.

In linguistic usage, peptida reflects language-specific naming for these molecules, while the English term remains peptide. The scientific concept remains that peptides are small to moderately sized amino acid chains with wide-ranging biological and chemical significance.