Protein synthesis, including polypeptide synthesis, occurs in the cytoplasm on ribonucleoprotein particles known as ribosomes. Messenger RNA (mRNA), which contains the code to direct the synthesis of one or several polypeptide chains, is synthesized by RNA polymerase on the DNA template and is then transported into the cytoplasm. Once in the cytoplasm, the mRNA becomes bound to the ribosomes buy bmk methyl glycidate and directs the placement of amino acyl-transfer RNAs in the proper sequence.
This process involves the activation of amino acids by binding to specific molecules of transfer RNA and their assembly by ribosomes into a sequence specified by the mRNA. Peptide bonds are then formed between adjacent amino acids, leading to the completion of the polypeptide chain. The subsequent folding, post-translational amino acid modifications, and protein packaging are all determined by the primary sequence of amino acids.
The termination of protein synthesis occurs at specific signals in the mRNA, and the process ceases when a ribosome reaches stop codons on the mRNA. Once proteins reach their appropriate subcellular location in the cell, they undergo final grooming and optimization through the removal of unnecessary subunits. This process represents the major route of disposal of amino acids, balancing the loss of cellular proteins through the production of new proteins.