Peptide chain elongation refers to the process in which a peptide chain, also known as a polypeptide chain, is lengthened during protein synthesis. Proteins are essential molecules in living organisms, responsible for carrying out various biological functions. Each protein is composed of one or more polypeptide chains that are made up of amino acids.
Peptide chain elongation occurs through a process called translation, which takes place in the ribosomes, the protein synthesis machinery. During translation, the ribosome reads the genetic information encoded in the messenger RNA (mRNA) molecule and uses it as a template to assemble the corresponding sequence of amino acids into a growing polypeptide chain.
The process begins with the initiation phase, where the ribosome recognizes a specific start codon on the mRNA, and an initiator tRNA brings the first amino acid, typically methionine, to the ribosome. Then, during the elongation phase, the ribosome sequentially adds amino acids to the growing polypeptide chain. Each amino acid is carried by a specific transfer RNA (tRNA) molecule and is matched with its corresponding codon on the mRNA.
The elongation process continues until a stop codon is reached, signaling the termination of translation and the completion of the polypeptide chain. Afterward, the newly synthesized polypeptide chain may undergo further modifications, such as folding into its three-dimensional structure or being processed into a mature functional protein. Peptide chain elongation is a crucial step in protein synthesis, playing a fundamental role in the creation of functional proteins necessary for life.
