Question

Which one of the following statements about peptide bonds is FALSE. Peptide bonds are:

a amides.
b involved in forming the primary structure of proteins.
c rigid and planar, with partial double-bond character.
d covalent.
e charged.

Answer 1

The FALSE statement among the options provided is "e) charged." Peptide bonds themselves do not carry a charge. Instead, charges in proteins typically arise from the side chains of amino acids, which can be positively charged (basic), negatively charged (acidic), or neutral depending on the pH of the environment. Peptide bonds, which link amino acids in a protein chain, are covalent and do not possess a net charge.

Step-by-step explanation

Peptide bonds are formed between amino acids during protein synthesis and are covalent in nature (option d). They are not charged, as charges are associated with the side chains of amino acids, not the peptide bond itself.

Peptide bonds contribute to the primary structure of proteins by linking amino acids in a linear sequence (option b). While peptide bonds do exhibit some double-bond character and planarity, they are not entirely rigid due to rotation around the alpha carbon (option c).

The term "amides" (option a) accurately describes the chemical nature of peptide bonds, as they involve an amide linkage between the carboxyl group of one amino acid and the amino group of another.