aminopäätyllä

Aminopäätyllä refers to the amino terminus of a polypeptide chain. This is the end of the peptide where the amino group of the N-terminal amino acid is free and not involved in peptide bond formation. In the standard representation of a protein or peptide sequence, the amino terminus is conventionally written on the left side. Each amino acid has an amino group and a carboxyl group. During peptide bond formation, the carboxyl group of one amino acid reacts with the amino group of another, forming a peptide bond and releasing a molecule of water. This process continues, creating a chain of amino acids linked by peptide bonds. The amino group of the very first amino acid in this chain remains unreacted, thus forming the amino terminus. The amino terminus is often important for protein function, as it can be involved in protein folding, interactions with other molecules, or serve as a target for post-translational modifications. Understanding the directionality of a polypeptide chain, from the amino terminus to the carboxyl terminus, is fundamental in molecular biology and biochemistry.