exam for trial

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Ambo University
College of medicine &Health science
biochemistry Test for Post Basic anesthesia year I
(BY Fikadu Seyoum)
Time Allowed 1:30hr, Exam Weight 20%
General Instruction
➢ Make sure that your phone is switched off
➢ Check that your exam has 6 pages including answer sheet
➢ Don’t forget to write all your personal files
➢ Any attempt to cheat will make your result null

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Part I……. true/false(each 0.5 point)
1.The rate of rxn of enzymatically catalyzed reaction increased beyond the optimum temperature
2.Chloride ion activates the action of thrombokinase enzyme
3.The rate of reaction is increased with time
4.The only lipid soluble vitamin use as coenzymes is vit-D
5.The deficiency of vit-B12absorptionprimary leads to megaloblastic anemia

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Part II……. Choice(each 0.5 point)
1.which one is not the non-protein part of Holoenzymes
A, Apoenzymes B, Cofactors C, Coenzymes D,Prosthetic group
2.select the true one regarding enzymes
A, All enzymes have both protein & non-protein part B, All enzymes are protein
C, Enzymes increase energy barrier of the rxn D ,Coenzymes are non-protein portion of holoenzyme
3.Most digestive enzymes like amylase,lipase,trypsin etc are classes of
A, Oxidoreductase B, Hydrolases C ,Lyases D,Transferases
4.Which properties of enzymes is not correct
A,They catalysis only forward reaction B,They speed up chemical rxn by changing equilibrium position
C, Most enzymes are not working in aqueous environment of living system D, All E, None
5.The coenzymes of compound enzymes are derivative of …………
A, Minerals B,Vitamins C, protein D,RNA
6.The special cleft/pocket of enzymes where substrate binds to for chemical reaction is called……
A, Allosteric site B, Regulatory site C, Active site D, Inhibitory site
7 Among the following which graph describe the substrate vs rate of reaction(enzyme action)
A,
8.True about factors affecting rate of enzymatically catalyzed reaction
A,The optimum PH for all enzymes working in our body system is similar
B,The effect of competitive inhibitors are reversed by increasing enzymes concentration
C, The optimum temperature of enzymes in all living organism is similar
D, Hexokinase enzyme is an example of transferases
9.Which one is true about the relationship b/n Menten constant(km) and its enzyme
A, Enzymes with high Menten constant (Km) implies that enzymes has high affinity to its substrate
B, Glucokinase act on glucose at low concentration(fasting state)
C, The Menten constant(km) equal to the substrate concentration at Vmax

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D, Enzyme is not fully saturated at Km=[s] E.All
10.which vitamin increase the absorption of Iron
A, vit-B12 B, vit-D C,vit-c D, vit-E
11.Tola is frequently consuming vegetables & fruits,b/c he dislikes animal product which vitamin is
probable deficient to him
A, vitamin C B, Cobalamine C,Vit- B6 D, All
12.The water soluble vitamin commonly use in amino acid metabolism is…..
A, Biotin B, vit-B6 C, Thiamine D,Niacin
13.The active form of which vitamin is used in the conversion of pyruvate to oxaloacetate
A, Ascorbate B, Riboflavin C, Biotin D,Coenzyme A
14.Rhodopsin the visual pigment of rod cells of retina of the eryes use vitamin A in the form of ….
A, All trans retinol B,All trans retinal C, 11-Cis retinol D,11-cis retinal
15.The predominant form of vitamin D in plasma is …..
A,Cholecalciferol B, 25-hydroxycholecalciferol C, 1,25 diOH-D3 D,7-Dehydrocholestirol

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Part III Writing(each 2 point)
1.Describe the way vitamin C leads to anemia
2,List at least three(3) vitamins that can be also provided by human GIT normal flora
3.Write the two chemical reaction in which vit -B12 use as coenzyme
4.Write enzymatic reaction steps
5.list & discuss the four(4) types of regulation of enzymatic action
BONUS(2point)
1.Compare and contrast the two models on mechanism of action of enzymatic activities

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Answer sheet
Name of student______________________________ID.NO_________Sign_________
Part I
1. 2. 3. 4. 5.
Part II
1. 2. 3. 4. 5.
6. 7. 8. 9. 10.
11. 12. 13. 14. 15.
Part III
1.
2.
3.
4.
5.
BONUS