What type of covalent bonds link the amino acids in a protein?

Correct option is A

Correct option: (a) Peptide bonds
Why (a) is correct:
· Amino acids are linked together by peptide bonds.
· A peptide bond forms between:
· The –COOH group of one amino acid
· The –NH₂ group of the next amino acid
· This bond formation releases one molecule of water (condensation reaction).
· Repeated peptide bonds form polypeptide chains, i.e., proteins.
❌ Why other options are incorrect
· (b) Hydrogen bonds
· These are weak, non-covalent bonds.
· They stabilize protein structure but do not link amino acids.
· (c) Glycosidic bonds
· Link monosaccharides in carbohydrates, not amino acids.
· (d) Ester bonds
· Found in lipids, linking fatty acids and glycerol.
�� Key Points
· Peptide bond = covalent bond in proteins.
· Proteins are polymers of amino acids.
· Hydrogen bonds stabilize secondary and tertiary structures, not primary structure.