Factors that affect enzyme: past paper questions
Real questions on factors that affect enzyme
The newest 20 of 71 written questions. Open one to see it on the real paper.
- 9700/41 · October/November 2025 · Q10[6]
Explain the relationship between genes, proteins and phenotype, with reference to two examples of genetic diseases in humans.
See it on the paper → - 9700/42 · October/November 2024 · Q10b[3]
Glycogen phosphorylase catalyses the conversion of glycogen to glucose in liver cells. The production of glycogen phosphorylase is coded for by the gene PYGL. A mutation in PYGL leads to a condition called glycogen storage disease type VI (GSDVI), in which glycogen is not broken down efficiently. Suggest and explain wh...
See it on the paper → - 9700/42 · October/November 2024 · Q10c[3]
Glycogen synthase catalyses the conversion of glucose to glycogen in liver cells. The production of glycogen synthase is coded for by the gene GYS2. A mutation in GYS2 leads to a condition called glycogen storage disease type 0 (GSD0) in which glycogen is not formed efficiently. Suggest what the consequences would be i...
See it on the paper → - 9700/41 · May/June 2024 · Q1b[4]
In anaerobic conditions, no ATP can be synthesised by oxidative phosphorylation because the process stops. Explain why ATP synthesis by oxidative phosphorylation stops in anaerobic conditions.
See it on the paper → - 9700/51 · October/November 2023 · Q2b(iv)[2]
Suggest explanations for the difference between the activity of the enzyme trypsin in Atlantic salmon and the activity of trypsin in domestic pigs.
See it on the paper → - 9700/51 · May/June 2023 · Q1a[1]
State one variable that should be standardised in the procedure to obtain the liquid carrot extract, other than the carrot tissue, fine sand and apparatus used. The student carried out these steps to investigate the activity of catalase in the different samples of carrot root tissue. • • • A disc of filter paper of 5 m...
See it on the paper → - 9700/51 · May/June 2023 · Q1b[1]
State the relationship between the time taken for the filter paper disc to rise to the surface of the hydrogen peroxide solution and the catalase activity of the liquid carrot extract. The student decided to investigate how catalase activity varies along the length of the carrot root. Fig. 1.5 shows a carrot. base of s...
See it on the paper → - 9700/51 · May/June 2023 · Q1c(i)[1]
Identify the independent variable in this investigation.
See it on the paper → - 9700/51 · May/June 2023 · Q1c(ii)[6]
Describe a method that the student could use to test the prediction that: As the distance from the base of the shoot increases, the catalase activity of carrot root tissue increases. Your method should be set out in a logical order and be detailed enough to allow another person to follow it. Details of how to use the c...
See it on the paper → - 9700/51 · May/June 2023 · Q1d(i)[1]
Identify the dependent variable in this investigation.
See it on the paper → - 9700/51 · May/June 2023 · Q1d(ii)[2]
To investigate the effect of hydrogen peroxide concentration on the activity of catalase in yeast, the student first prepared a range of known concentrations of hydrogen peroxide. The student was given a 6.0% stock solution of hydrogen peroxide. The student decided to use the stock solution to make hydrogen peroxide so...
See it on the paper → - 9700/51 · May/June 2023 · Q1d(iii)[3]
Fig. 1.7 shows the results of the investigation. 100 90 80 70 60 volume of gas collected after 1 minute / cm 3 50 40 30 20 10 0 0.0 1.0 2.0 3.0 4.0 5.0 6.0 7.0 percentage concentration of hydrogen peroxide Fig. 1.7 The student made two conclusions: • • As the concentration of hydrogen peroxide increases, the volume of...
See it on the paper → - 9700/52 · May/June 2023 · Q1b(i)[1]
Identify the independent variable in this experiment.
See it on the paper → - 9700/52 · May/June 2023 · Q1b(ii)[1]
Identify one variable that the student has standardised.
See it on the paper → - 9700/52 · May/June 2023 · Q1c(i)[2]
Use Fig. 1.2 to calculate the initial rate of this reaction in absorbance units per second (au s –1 ). Show your working. initial rate of reaction = au s –1
See it on the paper → - 9700/52 · May/June 2023 · Q1c(ii)[1]
Using the internet, the student found that pH 7.0 is the optimum pH for polyphenol oxidase. On Fig. 1.2, sketch the line you would expect to get for the rate of reaction at pH 3.0.
See it on the paper → - 9700/52 · May/June 2023 · Q1d[7]
The student wanted to determine the effect of the concentration of the substrate, dopamine hydrochloride solution, on the rate of the enzyme-catalysed reaction. The student was provided with a stock solution of 0.2% dopamine hydrochloride solution and the diluted enzyme extract prepared in (a). Describe a method the st...
See it on the paper → - 9700/52 · May/June 2023 · Q1e[2]
The browning of fruit such as bananas can make them more difficult to sell. One way to prevent browning of bananas is to use an anti-browning agent. The student searched the internet and found data from different scientific papers on the inhibitory effect of various anti-browning agents on polyphenol oxidase from diffe...
See it on the paper → - 9700/23 · October/November 2022 · Q2b(i)[3]
Calculate the percentage change in the number of new cases of TB in the USA between 1993 and 2018. Show all your working. answer %
See it on the paper → - 9700/53 · October/November 2022 · Q2c(ii)[3]
Gossypol produced by cotton plants can be found in two forms, the (–) isomer and the (+) isomer. The (–) isomer has higher biological activity within cells and is much more toxic than the (+) isomer. Both forms can bind protein to become bound gossypol. Table 2.2 summarises the mean daily gossypol intakes for the five...
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What examiners said
Several candidates were able to conclude that the activity of trypsin from Atlantic salmon was higher at 20 °C than the activity of trypsin from domestic pigs. To gain credit, candidates also needed to be able to explain this difference. Stating that the optimum temperature of trypsin from pigs is 38 °C, or that the optimum temperatures of trypsin from salmon and trypsin from pigs are different, d...
— Examiner report, October/November 2023, 9700/51 Q2(b)(iv) (Cambridge)
Most candidates were able to identify a variable that should be standardised. A significant number of candidates referred to carrot tissue even though the question stated this was not needed. Temperature was a very common incorrect answer.
— Examiner report, May/June 2023, 9700/51 Q1(a) (Cambridge)
The majority of candidates correctly identified that the time taken would decrease as catalase activity increased. Terms such as more, less, higher and greater were accepted but candidates should use increase and decrease when describing a relationship. Errors often occurred when candidates referred to faster rising of discs and concentrations of catalase. These responses were not creditworthy.
— Examiner report, May/June 2023, 9700/51 Q1(b) (Cambridge)
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