A-level BIOLOGY (7402/1)

A-level BIOLOGY (7402/1) Paper 1 Specimen 2023 Session Time allowed: 2 hours Materials For this paper you must have: • a ruler with millimetre measurements • a calculator. Instructions • Use black ink or black ball-point pen. • Fill in the boxes at the bottom of this page. • Answer all questions. Information • The marks for questions are shown in brackets. • The maximum mark for this paper is 91. Answer all questions in the spaces provided. A technician investigated the effect of temperature on the rate of an enzyme-controlled reaction. At each temperature, he started the reaction using the same concentration of substrate. Figure 1 shows his results. Give two other factors the technician would have controlled. [1 mark] 1 2 Draw a tangent on each curve to find the initial rates of reaction. Use these values to calculate the ratio of the initial rates of reaction at 60 ° C : 37 ° C. Show your working. [2 marks] Ratio = :1 Explain the difference in the initial rate of reaction at 60 ° C and 37 ° C. [2 marks] Explain the difference in the rates of reaction at 60 ° C and 37 ° C between 20 and 40 minutes. [4 marks]