polypeptidimolekyylien

Polypeptide molecules are polymers composed of amino acid residues linked by peptide bonds. Each monomer unit contains an amino group and a carboxyl group, which react to form a covalent amide bond that releases a molecule of water. The resulting chain can range in length from a few residues to several thousand, depending on the organism and the functional requirements of the protein.

The sequence of amino acids determines the chemical properties of a polypeptide, influencing its folding, stability, and interaction with other biomolecules. Basic folds such as α‑helices and β‑sheets emerge from hydrogen bonding patterns within the chain, providing the scaffold for tertiary and quaternary structure. Many polypeptide molecules function as enzymes, ligands, or structural components in cells.

In living systems, polypeptides are synthesized by ribosomes using messenger RNA as a template in a process called translation. The ribosome adds amino acids sequentially, guided by transfer RNAs that recognize codons. Post‑translational modifications such as phosphorylation or glycosylation can further modify the polypeptide, affecting its activity or localization.

Outside biology, synthetic polypeptides are produced by chemical or enzymatic polymerization techniques. They are used in biotechnology, drug delivery, and materials science. For example, polypeptide-based hydrogels can mimic extracellular matrices, and peptide amphiphiles are explored for targeted therapeutics.

The study of polypeptide molecules bridges biochemistry, molecular biology, and materials science. Understanding their synthesis, folding mechanisms, and functions remains essential for advances in medicine, agriculture, and nanotechnology.