Read the passage and answer the following questions:
Translation refers to the process of polymerisation of amino acids to form a polypeptide. The order and sequence of amino acids are defined by the sequence of bases in the mRNA. The amino acids are joined by a bond which is known as a peptide bond. Formation of a peptide bond requires energy.
Which bond joins the amino acids in a polypeptide?
Answer & explanation
Correct answer: option 2
The correct answer is Option (2) → Peptide bond
The passage states that “The amino acids are joined by a bond which is known as a peptide bond.” In translation, the amino acids carried by tRNAs are linked one after another by peptide bonds to form the polypeptide.
Option (1) Phosphodiester bond — Incorrect. A phosphodiester bond joins nucleotides in DNA and RNA through their sugar and phosphate. It does not link amino acids.
Option (2) Peptide bond — Correct. The peptide bond links one amino acid to the next in a polypeptide. It is formed in the ribosome.
Option (3) Hydrogen bond — Incorrect. Hydrogen bonds hold the bases of the two DNA strands together and pair the codon with the anticodon. They do not join amino acids into a chain.
Option (4) Glycosidic bond — Incorrect. A glycosidic linkage joins a nitrogenous base to the sugar in a nucleoside. It has no role in joining amino acids.