Which makes polypeptides?

Which makes polypeptides?

• A. Codon
• B. Ribosome
• C. tRNA
• D. Amino acid

Answer: (B)

Polypeptide synthesis occurs during translation on the ribosome, the molecular machine that reads the mRNA blueprint and links amino acids into a growing chain. The ribosome carries out peptide bond formation and coordinates the movement along mRNA, while aminoacyl-tRNAs bring the specific amino acids to be added. Codons in the mRNA determine which amino acid is incorporated, but they do not make polypeptides themselves. tRNA delivers the amino acids but does not assemble the chain on its own. Amino acids are the substrates, yet polymerization into a polypeptide happens at the ribosome. So, the ribosome is the correct choice because it is the site and catalyst of polypeptide synthesis.

Polypeptide synthesis occurs during translation on the ribosome, the molecular machine that reads the mRNA blueprint and links amino acids into a growing chain. The ribosome carries out peptide bond formation and coordinates the movement along mRNA, while aminoacyl-tRNAs bring the specific amino acids to be added. Codons in the mRNA determine which amino acid is incorporated, but they do not make polypeptides themselves. tRNA delivers the amino acids but does not assemble the chain on its own. Amino acids are the substrates, yet polymerization into a polypeptide happens at the ribosome. So, the ribosome is the correct choice because it is the site and catalyst of polypeptide synthesis.