CIE iGCSE Co-Ordinated Science B5. Enzymes Exam Style Questions Paper 4
Question
(a) Fig. 10.1 shows the effect of pH on the activity of one digestive enzyme.
(i) State the optimum pH for the enzyme as shown in Fig. 10.1.
(ii) Explain the effect on enzyme activity caused by pH 2 as shown in Fig. 10.1.
(b) State the name of the digestive enzyme that breaks down starch.
(c) State the optimum pH for the enzyme protease which is active in the stomach.
(d) Digestive enzymes break down large molecules into smaller molecules.
Table 10.1 shows information about some large food molecules.
Complete Table 10.1.
▶️Answer/Explanation
Ans :
10(a)(i) 8 ;
10(a)(ii) (no activity at pH2)
enzymes are denatured ;
(low / acidic, pH) causes shape of active site to change ;
substrate is no longer complementary to the, active site or enzyme ;
10(b) amylase ;
10(c) pH 1–3 ;
10(d) 