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Miracle Learning Centre Science Tuition Question on Enzyme.

(a) Fig. 1.1 shows apparatus at the start of an experiment to investigate the digestion of an emulsion of fat droplets in water by enzyme A.

The pH indicator is green in a pH of 7, blue when the pH is above 7 and red when it is below 7. The apparatus is kept at 40 °C for 20 minutes during which time the indicator changes from green to red. (i) State the identity of enzyme A. _____________________________ (ii) Explain why the apparatus was kept at 40 °C. _________________________________________________________ _________________________________________________________ _______________________________________________________ (b) Name the products of digestion of the emulsion by enzyme A. _____________________________________________________________ (c) Describe the processes which led to the change in pH. _______________________________________________________________ _______________________________________________________________ _______________________________________________________________ _______________________________________________________________ _______________________________________________________________ ____________________________________________________________ 2 (a) Explain the “lock and key” theory of enzyme action. Miracle Learning Centre Answer to Science Tuition Question on Enzyme (O Level Science Tuition/IP Science Tuition/Secondary Science Tuition) 1 (a) (i) State the identity of enzyme A. Lipase (ii) Explain why the apparatus was kept at 40 °C. optimum temperature + for enzyme/lipase action (b) Name the products of digestion of the emulsion by enzyme A. fatty acids + glycerol (c) Describe the processes which led to the change in pH. fatty acids/ref. smaller molecules (can) pass through partially permeable membrane/Visking tubing down a concentration gradient/ by diffusion acidity of or lowers pH of water/ref acidity of molecules changes the pH indicator [max 3] 2 (a) ref enzyme – lock/ active site; ref substrate – key; key fits lock / ref. Shape/ size/ specificity; ref enzyme-substrate complex; reaction while key in lock; products formed. [max 5] Learn from our Science Tuition Questions and Answers. Miracle Learning Centre Call 6463 8756 or sms 8128 8342/9839 9908. (Specialist in Science and Maths) for Primary, Secondary and JC levels. Miracle Learning Centre specialises in Science tuition, Maths tuition, Chemistry tuition and Physics tuition classes.