Figure 3 shows the activity of the enzymes pepsin and trypsin at different pH levels - Edexcel - GCSE Biology Combined Science - Question 3 - 2019 - Paper 1
Question 3
Figure 3 shows the activity of the enzymes pepsin and trypsin at different pH levels.
(i) Describe the trend in the graph for the enzyme trypsin.
Use data from the ... show full transcript
Worked Solution & Example Answer:Figure 3 shows the activity of the enzymes pepsin and trypsin at different pH levels - Edexcel - GCSE Biology Combined Science - Question 3 - 2019 - Paper 1
Step 1
Describe the trend in the graph for the enzyme trypsin.
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Answer
The graph shows that trypsin activity increases as the pH rises from 1 to 7, reaching a peak at around pH 8, where it demonstrates maximum enzyme activity. Beyond pH 8, the activity starts to decline, indicating that trypsin is not effective at higher pH levels.
Step 2
State the optimum pH for the enzyme pepsin.
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Answer
The optimum pH for the enzyme pepsin is approximately pH 2.
Step 3
Describe the conditions in the stomach that allow pepsin to work effectively.
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Answer
The stomach is an acidic environment, typically with a pH around 1.5 to 3.5. This high acidity is crucial for activating pepsin from its inactive form and allows it to effectively break down proteins. Additionally, the presence of gastric juices facilitates the enzymatic action of pepsin.
Step 4
At high pH values the active site of the enzyme pepsin changes shape.
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Answer
B denatured
Step 5
State what is produced when proteins are digested.
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Amino acids are produced when proteins are digested.