Biological molecules: past paper questions
Real questions on biological molecules
The newest 20 of 45 written questions, plus 50 multiple-choice. Open one to see it on the real paper.
- 0970/31 · May/June 2026 · Q2c(ii)[1]
Water is a liquid that dissolves substances. State the name given to liquids that can dissolve substances.
See it on the paper → - 0970/32 · May/June 2026 · Q1a(ii)[1]
Pectinase breaks down the carbohydrate pectin. Pectin is found in the cell walls of many types of fruit. State the name of one other carbohydrate found in plant cell walls.
See it on the paper → - 0970/41 · May/June 2026 · Q2b[1]
Starch is a carbohydrate. State the elements that are in all carbohydrates.
See it on the paper → - 0970/41 · May/June 2026 · Q2c[2]
Table 2.1 shows some information about large molecules and the smaller molecules they are made from. Complete Table 2.1. Table 2.1 large molecule small molecules glycogen cellulose amino acids fatty acids and glycerol
See it on the paper → - 0970/42 · May/June 2026 · Q4a[1]
List the chemical elements that are found in all carbohydrates. Figure 4.1 (i) State the letter of the structure shown in Figure 4.1 that: produces urea produces pepsin (ii) Structure M in Figure 4.1 releases a hormone that increases blood glucose concentration. State the name of this hormone and explain how it increas...
See it on the paper → - 0970/61 · May/June 2026 · Q3c[1]
Fertilisers contain nitrates which are used by plants to make proteins. State the name of the solution used to test for protein.
See it on the paper → - 0970/62 · May/June 2026 · Q1a(i)[1]
step 3 step 4 step 5 step 6 step 7 step 8 step 9 step 10 step 11 step 12 Complete Table 1.1 by writing in the final percentage concentration of vitamin C solution in test-tube V3. Table 1.1 volume of oe final percentage beaker 0.6% vitamin C volume of distilled concentration of Rien 3 water W/cm? ar P solution V/cm vit...
See it on the paper → - 0970/62 · May/June 2026 · Q1a(ii)[3]
Prepare a table and record the results shown in Figure 1.1. Include the final percentage concentrations of the vitamin C solutions in your table.
See it on the paper → - 0970/62 · May/June 2026 · Q1a(iii)[1]
(iii) Calculate the volume of iodine solution added to each test-tube. Use the formula shown: volume of iodine solution added = 5.0 — the volume remaining in the syringe teSttUDe .......... tESt-tUD@ .......... tESt-tUDG ..........
See it on the paper → - 0970/62 · May/June 2026 · Q1a(iv)[1]
State the dependent variable in this investigation.
See it on the paper → - 0970/62 · May/June 2026 · Q1a(v)[1]
Explain why a blue-black colour was seen when iodine solution was added to the test-tubes.
See it on the paper → - 0970/62 · May/June 2026 · Q1a(vi)[1]
The student used the same syringe to add the vitamin C solution in step 5, step 6 and step 7. Suggest what effect this would have on the volume of iodine solution required for the mixture in test-tube V3 to remain blue-black.
See it on the paper → - 0970/62 · May/June 2026 · Q1a(vii)[1]
Another student repeated the investigation but counted the number of drops of iodine solution added instead of measuring the volume. Suggest why measuring volume is more accurate than counting drops.
See it on the paper → - 0970/62 · May/June 2026 · Q1b(i)[1]
(i) Table 1.2 shows the volumes of iodine solution the student recorded in step 18 and step 19. Table 1.2 volume of iodine solution added to drink D/cm? 2.8 2.9 2.7 Calculate the mean volume of iodine solution added to drink D. mean volume iodine solution added drink .......... [1]
See it on the paper → - 0970/62 · May/June 2026 · Q1b(ii)[1]
(ii) Use your answers in 1(a)(iii) and 1(b)(i) to estimate the vitamin C concentration in drink D. estimated vitamin concentration drink .......... .......... .......... teeteeteeeeteeenees [1]
See it on the paper → - 0970/62 · May/June 2026 · Q1b(iii)[1]
Describe one modification to the procedure in 1(a) that would allow you to have more confidence in your estimate in 1(b)(ii).
See it on the paper → - 0970/62 · May/June 2026 · Q1b(iv)[2]
The manufacturer of a drink claims that it does not contain reducing sugars. Describe a test that would confirm the presence of reducing sugars.
See it on the paper → - 0970/62 · May/June 2026 · Q1b(v)[1]
(v) State one other test that could be used to determine the presence of vitamin C. dace .......... [1]
See it on the paper → - 0970/62 · May/June 2026 · Q1c(ii)[2]
Describe and explain the change in the vitamin C concentration in the kiwi fruit in Table 1.3.
See it on the paper → - 0970/62 · May/June 2026 · Q1c(iii)[2]
(iii) Use your graph to estimate the vitamin C concentration in kiwi fruit that has been dried for 10 hours. Indicate on your graph how you obtained your answer. .......... 100g kiwi fruit [2]
See it on the paper →
What examiners said
Many candidates were awarded full marks here. Common errors were phagocytosis and enzyme.
— Examiner report, May/June 2025, 0970/31 Q5(c)(i) (Cambridge)
Many candidates gave examples of molecules rather than the three elements.
— Examiner report, May/June 2025, 0970/32 Q6(b)(i) (Cambridge)
Almost all candidates knew that cellulose builds cell walls. The most common incorrect answers were starch, glucose and lignin.
— Examiner report, May/June 2025, 0970/42 Q4(c)(ii) (Cambridge)
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