4. The table shows some of the enzymes involved in the digestion of starch, protein and fat, in three parts of the digestive system - Edexcel - GCSE Biology - Question 4 - 2012 - Paper 1
Question 4
4. The table shows some of the enzymes involved in the digestion of starch, protein and fat, in three parts of the digestive system.
Part of digestive system | Subs... show full transcript
Worked Solution & Example Answer:4. The table shows some of the enzymes involved in the digestion of starch, protein and fat, in three parts of the digestive system - Edexcel - GCSE Biology - Question 4 - 2012 - Paper 1
Step 1
Enzyme Q is produced by the
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Answer
Enzyme Q is produced by the D pancreas. The pancreas secretes various enzymes, including amylase for starch digestion.
Step 2
Molecules Y and Z are
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Molecules Y and Z are B fatty acids and glycerol, which are produced from the digestion of fats.
Step 3
Name enzyme R.
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Enzyme R is protease or pepsin, an enzyme that digests proteins.
Step 4
Name molecule W.
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Molecule W is amino acids, which are the resulting product from the digestion of proteins.
Step 5
Calculate the difference in the rate of the reaction between pH 1 and pH 2.
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The difference in the rate of the reaction between pH 1 and pH 2 is 3 arbitrary units (rate at pH 1 is 12 units, and at pH 2 is 9 units).
Step 6
Suggest why this enzyme works better at pH 1 than at pH 2.
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The enzyme works better at pH 1 because at this pH, the active site is optimal for substrate binding, leading to more successful collisions. At pH 2, the enzyme's shape may be distorted, reducing its effectiveness.
Step 7
Explain the roles of bile in digestion.
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Bile plays a crucial role in digestion by emulsifying fats, which increases the surface area for enzyme action. It also helps in the absorption of fat-soluble vitamins and neutralizes stomach acid in the small intestine.
