Biology > QUESTION PAPER & MARK SCHEME > AQA A-level BIOLOGY 7402/1 Paper 1 Question Paper + Mark scheme (Merged) GRADE A+ (All)

AQA A-level BIOLOGY 7402/1 Paper 1 Question Paper + Mark scheme (Merged) GRADE A+

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AQA A-level BIOLOGY 7402/1 Paper 1 Question Paper + Mark scheme (Merged) June 2021 Version: 1.0 Final *JUN217402101* IB/H/Jun21/E14 7402/1 For Examiner’s Use Question Mark 1 2 3 4 5 ... 6 7 8 9 10 TOTAL Time allowed: 2 hours Materials For this paper you must have: •a ruler with millimetre measurements •a scientific calculator. Instructions •Use black ink or black ball-point pen. •Fill in the boxes at the top of this page. •Answer all questions. •You must answer the questions in the spaces provided. Do not write outside the box around each page or on blank pages. •If you need extra space for your answer(s), use the lined pages at the end ofthis book. Write the question number against your answer(s). •Show all your working. •Do all rough work in this book. Cross through any work you do not want to be marked. Information •The marks for the questions are shown in brackets. •The maximum mark for this paper is 91. Please write clearly in block capitals. Centre number Candidate number Surname Forename(s) Candidate signature I declare this is my own work. A-level BIOLOGY Paper 1 2 *02* IB/H/Jun21/7402/1 Do not write outside the box Answer all questions in the spaces provided. 0 1 . 1 Describe the induced-fit model of enzyme action and how an enzyme acts as a catalyst. [3 marks] 0 1 . 2 Scientists investigated the action of the enzyme ATP synthase. They made reaction mixtures each containing: • ATP synthase • buffer (to control pH) • substrates. One of the substrates required in these reaction mixtures is inorganic phosphate (Pi). Tick () one box to show which other substrate the scientists must add to the reaction mixtures to produce ATP. [1 mark] Adenine Adenosine diphosphate Glucose Ribose 3 *03* Turn over ► IB/H/Jun21/7402/1 Do not write outside the box 0 1 . 3 The scientists investigated the effect of concentration of inorganic phosphate (Pi) on ATP synthase activity. After 2 minutes, they stopped each reaction and then measured the concentration of ATP. Figure 1 shows the scientists’ results. Figure 1 Suggest and explain a procedure the scientists could have used to stop each reaction. [2 marks] 0 1 . 4 Explain the change in ATP concentration with increasing inorganic phosphate concentration. [2 marks] 8 4 *04* IB/H/Jun21/7402/1 Do not write outside the box 0 2 . 1 Explain the advantage for larger animals of having a specialised system that facilitates oxygen uptake. [2 marks] [Show More]

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