Page 42 - Ranger SPM 2022 Biology

Biology SPM SPM Model Paper
2. Figure 2 shows a process which takes (b) The above process is catalysed
place in green leaves of plants. by the enzyme sucrase. Only
a little sucrase is used in the
A B reaction.
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(i) By using the lock and key
hypothesis, explain how
sucrase catalyses the
process.
[2 marks]
(ii) Explain why only a little
C sucrase is needed for the
D above reaction.
Figure 2 [1 mark]

(a) (i) What is the process shown (c) Enzymatic reactions can be
in Figure 2? inhibited by chemicals called
[1 mark] inhibitors. Figure 3.2 shows a
box of statin, a medicine which is
(ii) Write an equation in words to prescribed by doctors to reduce
describe the process. the level of blood cholesterol
[1 mark] (LDL). Statin is an inhibitor for the
enzymatic reaction.
(b) Describe the pathways in which
molecules A and B enter cells of
leaves.
[2 marks]
(c) Explain what happens to molecule
D after it has been synthesised in
leaves.
[2 marks]

3. Figure 3.1 shows dissociation of a
sucrose molecule.
Figure 3.2
+ H O +
2
Based on your knowledge in
Figure 3.1 biology, explain how statin is
used to reduce blood cholesterol
Based on Figure 3.1, level.
[2 marks]
(a) Describe the above process.
[2 marks]

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Model Paper.indd 388 3/29/22 5:22 PM