The peptide AQGAL has:Group of answer choicesFour peptide bondsTwo free amino groupsNo free carboxylate groupsA disulphide bridge PreviousNext

The correct answer is "Four peptide bonds."

A peptide bond is a chemical bond formed between two amino acids when the carboxyl group of one amino acid reacts with the amino group of the other amino acid. The peptide AQGAL is made up of five amino acids (A for Alanine, Q for Glutamine, G for Glycine, A for Alanine, and L for Leucine). Therefore, it has four peptide bonds, one between each pair of adjacent amino acids.

The other options are incorrect. The peptide has only one free amino group (at the N-terminus) and one free carboxylate group (at the C-terminus), not two. And there is no cysteine in the peptide sequence, so it cannot form a disulfide bridge.