Get premium membership and access revision papers, questions with answers as well as video lessons.
Basic Metabolism Ii Question Paper
Basic Metabolism Ii
Course:Bachelor Of Science In Biochemistry
Institution: Egerton University question papers
Exam Year:2005
UNIVERSITY EXAMINATIONS
SECOND SEMESTER 2004/2005
BIOC 202: BASIC METABOLISM 11
TIME:3 HRS
INSTRUCTIONS
Attempt ALL questions.
SECTION A: 15 marks each
1.Give a detailed outline of the biosynthesis of cholesterol and highlight its clinical significance.
2.Discuss in detail,the urea cycle,highlighting the genetic defects associated with it.
SECTION B:marks each
3.(i) [9-14C] palmitate is oxidized under conditions in which citric acid cycle is operating.Illustrate the location of the 14C in:
(a) acetyl CoA
(b) Citrate
(ii) Write the overall equation for the complete oxidation of palmitic acid.
4.Outline the oxidation of propionate,illustrating the role of biotin.
5.In cases of severe diabetes,the patients tissue cannot utilize glucose but instead,they oxidize large amount of fatty acids to acetyl-bA.
(i) Why must mitochondria convert the acetyl CoA to ketone bodies.
(ii) Discuss the synthesis and utilization of ketone bodies.
6.List five enzymes found in the fatty acid synthase complex and their roles in fatty acid synthesis.
7.Write the reactions catalyzed by the following enzymes:-
(i) ß-ketoacyl-ACP-synthase
(ii) Phosphatidate phosphatase
(iv) Thiolase
8.Illustrate the interrelation in the synthesis of phosphatidyl choline,phosphatidyl ethanolamine and phosphatidyl serine in eukaryotes.
SECTION C (1mark each)
9.(i) Which of the following combinations of coenzymes are necessary for ß-oxidation.
(a) NAD+,FADH2,coenzyme A
(b) NAD+,FAD,Coenzyme A
(c) Acetyl CoA,NAD+,FAD
(d) NADH,Coenzyme A,FAD
(e) Acetyl CoA,FADH2,NAD+
(ii) Vitamin B6 functions as a coenzyme for many enzyme reactions in amino acid metabolism because it can:-
(a) Help in the dehychogenation between the 8-amino and the 8-carbon atoms
(b) Form a schiff base with the enzyme
(c) Form a Schiff base with the amino acid and that intermediate facilitates migration of migration of electrons away from bonds to be cleared.
(d) Acts as an electrophille
(e) Acts as a nucleophille.
(iii) Which of the following statements relating to urea cycle is correct?
(a) It takes place entirely within mitochondria
(b) It takes place within the cytosol
(c) It results in the conversion of CO2 and free ammonia into urea.
(d) It involves no amino acid.
(e) It requires the participation of aspartarte and indirectly glutamate.
(iv) Which of the following compounds contain carbon atoms not derived from glutamate or glutamine?
(a) Arginine
(b) Gysteine
(c) (c) Spermine
(d) Sermic
(e) Urea
(v) Which of the following is correct?The biosynthesis of triacyl glycerols involves:
(a) Sphingosine
(b) Pancreatic lipase
(c) Gly cerol-3-phosphate
(d) Dihydroxyacetone phosphate.
(vi) Which of the following is correct.The biosynthesis of sphingomyelins involves:
(a) Fatty acyl CoA
(b) Glycerol kinase
(c) NADPH-linked reduction
(d) CDP-choline
(vii) Mevalonate is a key intermediate concerned with isoprenoid biosynthesis and is formed by reduction of HMG-CoA.
Which of the following statement is correct?
(a) Mevalonate is a branched-chain C5 compound.
(b) The reducing equivalents required for mevalonate formation are supplied by NADH
(c) HMG-CoA may also be utilized for ketone body formation
(d) Mevalonate reacts with ATP at the carboxyl group
(e) Synthesis of HMG-CoA from acetyl-CoA requires three condensation steps.
(f) (viii) Biosynthesis of isoprenoid-derived utilizes the reactive intermediate isopentenyl-pp.Which of the following statement is correct.
(a) Isopentenyl-pp is reactive because it contains a branched methyl group.
(b) Isopentenyl-pp initially reacts with isomeric dimethyl-allyl derivative.
(c) Condensation reactions leading to longer-chain products always involve dimethl allyl-pp
(d) Pyrophosphate is released in the reaction described in (b).
(ix) Which of the following is a glycolipid?
(a) Sphingomyelin
(b) Lecithin
(c) Cardiolipin
(d) Cerebroside
More Question Papers