CENTRE FOR FOUNDATION STUDIES
FOUNDATION IN SCIENCE
MAY 2013
FHSB1214
BIOLOGY I
TUTORIAL 3
ENZYMOLGY ESSENTIAL
Student’s Guide:
At university level, the tutor facilitates student learning without spoon-feeding. Therefore, you are expected to:
• Read your textbook, attempt the questions before the tutorial • You may enter the class and sign your attendance after showing your tutor that all tutorial questions have been completed; even if you don’t know how to do, write something - you’re not advised to leave answers blank in the finals. • Write answers on board if you wish to receive tutor feedback (no answer, no feedback) • Be independent: consult textbooks or dictionaries on your own first before asking the tutor • All questions are compulsory. 1 mark may reflect 1 answer point. (No half mark is awarded in the finals marks)
(Source: Final examination, Apr 2013)
Q1. Lipase is an enzyme that can digest lipids. An experiment was set up to study the effect of temperature on the action of lipase enzyme. Nine test tubes were prepared separately and the experimental set up was designed in a way as shown in Figure 1.1. The nine test tubes which contain 10cm3 of corn oil and 1cm3 of lipase were kept at a range of temperatures between 20°C and 100°C. At the start of the experiment, the pH of the contents in each test tube was constant, which was 6.5.
[pic] Figure 1.1
Each test-tube was left for 30 minutes and the reading on the digital pH meter was then recorded. The pH readings against different temperatures are plotted in a graph, shown in Figure 1.2.
[pic] Figure 1.2
(i) State the products of hydrolyzed corn oil. (2 marks)
(ii) With reference to Figure 1.2, state the optimum temperature for lipase to perform its catalytic activity. (1 mark)