22 8 The graph shows the results of an experiment investigating the effect of temperature on the hydrolysis of starch using the enzyme amylase. 0 1 2 3 4 5 6 7 10 8 6 4 2 0 Concentration of maltose produced mmol dm–3 Time / hours 55 °C 65 °C (a) Calculate the initial rate of reaction at 55 °C in mmol dm–3 min–1. (2) Answer .............................................................. 23 Turn over (b) Explain the difference between the two curves from 4 and 6 hours. 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(c) In this experiment:  two beakers were prepared containing 1cm3 of amylase and 100 cm3 of starch solution at room temperature  these beakers were then placed in the water baths at two different temperatures, 55 °C and 65 °C  every 30 minutes a sample of the mixture was extracted and the concentration of maltose was measured. (i) Analyse the information to explain why the initial rate of this reaction was faster at 65 °C than it was at 55 °C. 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(Total for Question 8 = 13 marks) TOTAL FOR PAPER = 80 MARKS 26 BLANK PAGE 27 BLANK PAGE 28 BLANK PAGE