The following statements are features of an enzyme from a healthy human.
1 It works at an optimum pH below 4.
2 It digests a substrate into amino acids.
3 It works at an optimum temperature of approximately C.37°
Which enzyme has these features?

Answer:

9) F

Sentence 2 helps us to identify the type of enzyme.

Amylase breaks starch into glucose
Lipase breaks lipids into fatty acids and glycerol
Proteases breaks proteins into amino acids
Hence, the enzyme is protease. This rules out options A, B, C and D.

Sentence 1 helps us to know that pH is acidic. We know that the stomach secrets hydrochloric acid. Therefore, the answer is F ‘protease from the stomach’