LOYOLA COLLEGE (AUTONOMOUS), CHENNAI – 600 034
M.Sc. DEGREE EXAMINATION - BIO TECHNOLOGY
SECOND SEMESTER – APRIL 2012
BT 2818 - ENZYMOLOGY & ENZYME TECHNOLOGY
Date : 19-04-2012
Time : 9:00 - 12:00
Dept. No.
Max. : 100 Marks
PART – A
Answer all the questions:
I. Choose the correct answer:
(20 marks)
(5×1 = 5)
(1) Formation of C-C bonds coupled with ATP cleavage is catalyzed by
(a) Hydrolase (b) Isomerase (c) Oxidoreductase (d) Ligase
(2) The inhibition mechanism of pyruvate kinase by alanine is
(a) Competitive (b) Non–competitive (c) Irreversible (d) Continuous
(3) Which one of the following subunits of α-keto acid dehydrogenase complex catalyzes decarboxylation
of amino acids?
(a) E1
(b) E2
(c) E3
(d) E4
(4) Elevated levels of serum LDH1 indicates
(a) Liver disorder (b) Tay-Sachs disease (c) Immunodeficiency (d) Myocardial infarction
(5) Which one of the following enzymes is used in detergents?
(a) Pectinase (b) Xylanase (c) Laccase
(d) Protease
II. State whether the following are True or False, if false give reason:
(5×1= 5)
(6) Most enzymes are specific for a given stereoisomer of a substrate.
(7) Once a zymogen is activated it cannot revert back to its inactive state.
(8) Bromelain is obtained from marine algae.
(9) Mannosidosis leads to accumulation of cerebrosides in the lysosomes.
(10) Thermostability of the enzyme can be improved by introducing proline residues at specific positions
in the enzyme structure.
III. Complete the following:
(5×1 = 5)
(11) Enzymes that catalyze the addition of groups to double bonds are called as _______
(12) The catalytic constant kcat is known as the _______ number.
(13) The catalytic amino acids in the active site of lysozyme are _______ and _______
(14) The first successful enzyme therapy was done for _______
(15) Chill haze in beer is prevented by the enzyme _______
IV. Answer the following questions, each in about 50 words only:
(16) Give two examples of coenzymes.
(17) Define enzyme activity.
(18) Define isozymes.
(19) What are leakage enzymes?
(5×1 = 5)
(20) What is the role of ‘mediators’in an enzyme electrode?
PART – B
(5×8 = 40 marks)
Answer the following questions, each in 500 words; Draw diagrams wherever necessary.
21(a) Explain the following:
(i) IUBMB nomenclature (ii) Zymogens
OR
(b) How do enzymes decrease the activation energy? What modifications does the substrate undergo
while interacting with the active site of the enzyme?
22(a) Explain the different types of enzyme inhibition.
OR
(b) Write notes on:
(i) Thermodynamics of enzyme reactions
(ii) Specific activity
23(a) Enlist any two enzymes produced by two different bacteria, fungi, plant and animal sources.
OR
(b) Give an account on the points to be kept in mind while performing cDNA synthesis and while using
yeast expression systems during expression cloning.
24(a) Write notes on:
(i) Diagnostic enzymes for prostate cancer (ii) Glycogen storage disease
OR
(b) Discuss briefly the following:
(i) Hereditary coproporphyria
(ii) Accurate interpretation of serum enzyme assays
25(a) Write a note on enzyme immobilization.
OR
(b) Give an account on random mutagenesis with degenerate oligonucleotide primers.
PART – C
Answer any TWO of the following questions, each within 1500 words:
Draw diagrams wherever necessary.
(2×20 = 40 marks)
(26) Discuss in detail the isolation and purification of enzymes.
(27) Give a detailed account on enzyme replacement therapy with suitable examples.
(28) Explain the following:
(i) Molecular screening for enzymes
(ii) Criteria to be considered for production of microbial enzymes
(29) Discuss the following:
(i) Engineering Fok I endonuclease for substrate specificity
(ii) Improving enzyme stabililty by addition of disulphide bonds and changing of asparagines and
glutamine residues.
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