What enzymes break down proteins into amino acids?

• A. Proteases
• B. Lipases
• C. Amylases
• D. Nucleases

Answer: (A)

Proteases are the enzymes that break down proteins by hydrolyzing the peptide bonds between amino acids. This action gradually converts large proteins into smaller pieces and ultimately into free amino acids that the body can absorb and use. In digestion, proteases work in different places: stomach enzymes like pepsin start protein breakdown, and pancreatic enzymes such as trypsin and chymotrypsin continue the process in the small intestine, with brush-border peptidases finishing the job.

Other enzyme types act on different macromolecules—lipases break down fats into fatty acids and glycerol, amylases break down carbohydrates into sugars, and nucleases break down nucleic acids into nucleotides. Since the question asks for breakdown into amino acids, proteases are the correct and best choice.