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IGCSE Combined Science 0653 · Biology · 37

0653.B7.3.04 — Describe the functions of enzymes as follows: (a). amylase breaks down starch to simple reducing sugars (b). proteases break down protein to: past paper questions

7 real questionsasked in 6 of the last 10 exam series2023–2025usually: State, Complete, Name, Explain

Real questions on 0653.b7.3.04 — describe the functions of enzymes as follows: (a). amylase breaks down starch to simple reducing sugars (b). proteases break down protein to

The newest 7 of 7 written questions. Open one to see it on the real paper.

  1. 0653/32 · May/June 2025 · Q3b(ii)[2]

    Fats are digested in the small intestine. Name the two smaller molecules that fats are made from. and

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  2. 0653/42 · February/March 2025 · Q1c(i)[2]

    Complete these sentences about the chemical digestion of starch. Starch is broken down by the enzyme .

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  3. 0653/42 · February/March 2025 · Q1c(ii)[1]

    Explain why starch needs to be digested before it is absorbed.

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  4. 0653/43 · October/November 2024 · Q4b[4]

    Starch is part of a balanced diet for humans. Complete the sentences about starch digestion in the human alimentary canal. Starch is digested by an enzyme called . The enzyme breaks down starch molecules into smaller carbohydrate molecules called . The enzyme is secreted into the mouth from the glands and into the

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  5. 0653/43 · May/June 2024 · Q4a(iii)[1]

    State the name of the product when proteins are digested.

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  6. 0653/42 · February/March 2024 · Q1c[2]

    Enzymes in the alimentary canal speed up chemical digestion. State the function of the enzyme amylase.

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  7. 0653/43 · October/November 2023 · Q4a(ii)[2]

    Starch is digested by an enzyme in the alimentary canal. State the name of the enzyme and of the product of this digestion. enzyme product

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What examiners said

Candidates found this question demanding. Many candidates stated fatty acids, but fewer stated glycerol. Candidates are reminded that several food materials are made from larger molecules that must be digested into smaller molecules before they can be absorbed into the blood. In the case of fats, the two smaller molecules are fatty acids and glycerol.

— Examiner report, May/June 2025, 0653/32 Q3(b)(ii) (Cambridge)

Credit was very frequently awarded to candidates who identified amylase, but fewer gained the credit for reducing sugars. Alternative answers that gained credit were carbohydrase for amylase and glucose or maltose for reducing sugar.

— Examiner report, February/March 2025, 0653/42 Q1(c)(i) (Cambridge)

Many correct definitions of what happens during chemical digestion were seen but to gain credit, candidates had to refer to either the influence of molecular size or molecular solubility on absorption.

— Examiner report, February/March 2025, 0653/42 Q1(c)(ii) (Cambridge)

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0653.B7.3.04 — Describe the functions of enzymes as follows: (a). amylase breaks down starch to simple reducing sugars (b). proteases break down protein to — IGCSE Combined Science 0653 past paper questions | AssessPro