Carbohydrates Biochemistry Set 5

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Biochemistry (Carbohydrates And Carbohydrate Metabolism Set 5)

MCQ

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1. The conversion of pyruvate to acetyl CoA
and CO2

A) Depends on the coenzyme biotin

B) Occurs in the cytosol

C) Involves the participation of lipoic acid

D) Is reversible

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2. Glycogen is present in all body tissues
except

A) Stomach

B) Kidney

C) Brain

D) Liver

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3. How many ATPs are produced in the
conversion of phosphoenol pyruvate to
citrate

A) 4

B) 6

C) 2

D) 1

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4. Under standard conditions

A) The standard free energy change ∆G, is equal to 0

B) The free energy change ∆G°, is equal to 0

C) The free energy change, ∆G°, is equal to the standard free energy change, ∆G°

D) Keq is equal to 1

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5. How many ATP molecules will be required
for conversion of 2-molecules of Lactic acid
to Glucose

A) 4

B) 8

C) 6

D) 2

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6. Which one of the following compounds
cannot give rise to the net synthesis of
Glucose

A) Acetyl CoA

B) α-ketoglutarate

C) Lactate

D) Glycerol

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7. Electron transport and phosphorylation
can be uncoupled by compounds that
increase the permeability of the inner
mitochondrial membrane to

A) Uncouplers

B) All of these

C) Electrons

D) Protons

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8. Which one of the following statements
concerning glucose metabolism is correct

A) The conversion of Glucose to lactate occurs only in the R.B.C

B) Pyruvate kinase catalyses an irreversible reaction

C) Glucose enters most cells by a mechanism in which Na+ and glucose are co-transported

D) An elevated level of insulin leads to a decreased level of fructose 2, 6-bisphosphate in hepatocyte

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9. Phenylalanine is the precursor of

A) Histamine

B) L-DOPA

C) Throxine

D) Tyrosine

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10. Out of 24 mols of ATP formed in TCA cycle,
2 molecules of ATP can be formed at
“substrate level” by which of the
following reaction

A) Citric acid→ Isocitric acid

B) Succinylcat→ Succinic acid

C) socitrate→ Oxaloacetate

D) Succinic acid→ Fumarate

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11. All of the following statements about the
enzymic complex that carries out the
synthesis of ATP during oxidative
phosphorylation are correct except

A) It is located on the matrix side of the inner mitochondrial membrane

B) ) It can bind molecular O2

C) It can exhibit ATPase activity

D) It is inhibited by oligomycin

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12. Glucokinase

A) Is widely distributed in Prokaryotes

B) Is widely distributed and occurs in most mammalian tissues

C) Has a high km for glucose and hence is important in the phosphorylation of glucose primarily after ingestion of a carbohydrate rich meal

D) None of these

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13. Cori cycle is

A) Synthesis of glucose

B) reuse of glucose

C) Both (A) & (B

D) uptake of glycose

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14. Which one of the following would be
expected in pyruvate kinase deficiency

A) Hemolytic anemia

B) Increased phosphorylation of Glucose to Glucose-6-phosphate

C) Decreased ratio of ADP to ATP in R.B.C

D) Increased levels of lactate in the R.B.C

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15. An allosteric enzyme responsible for
controlling the rate of T.C.A cycle is

A) Aconitase

B) Isocitrate dehydrogenase

C) Malate dehydrogenase

D) Fumarase

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16. In presence of the following cofactor,
pyruvate carboxylase converts pyruvate
to oxaloacetate

A) ATP, Protein and CO2

B) Protein

C) CO2 and ATP

D) CO2

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17. The more positive the E0, the greater the
tendency of the oxidant member of that
pair to

A) Lose and gain electrons

B) Gain electrons

C) Lose electrons

D) Lose (or) gain electrons

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18. An uncoupler of oxidative phosphorylation such as dinitropheno

A) Specially inhibits cytochrome b

B) Inhibits electron transport without impairment of ATP synthesis

C) Inhibits electron transport and ATP synthesis

D) Allow electron transport to proceed without ATP synthesis

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19. Reduced glutathione functions in R.B.Cs
to

A) Produce NADH

B) Reduce methemoglobin to hemoglobin

C) Produce NADPH

D) Reduce oxidizing agents such as H2O2

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20. Phenylalanine is the precursor of

A) Throxine

B) Histamine

C) L-DOPA

D) Tyrosine

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21. The reaction catalysed by phosphofructokinase

A) Is inhibited by fructose 2, 6-bisphosphate

B) Is the rate-limiting reaction of the glycolytic pathway

C) Is activated by high concentrations of ATP and citrate

D) Uses fruitose-1-phosphate as substrate

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22. Compared to the resting state, vigorously
contracting muscle shows

A) A decreased NADH/NAD+ ratio

B) Decreased oxidation of pyruvate of CO2 and water

C) Decreased concentration of AMP

D) An increased conversion of pyruvate to lactate

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23. The reaction catalysed by phosphofructokinase

A) Is the rate-limiting reaction of the glycolytic pathway

B) Uses fruitose-1-phosphate as substrate

C) Is activated by high concentrations of ATP and citrate

D) Is inhibited by fructose 2, 6-bisphosphate

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24. For conversion of oxaloacetate to
phosphoenol pyruvate, high energy
molecule is required in the form of

A) None of these

B) ITP only

C) GTP (or) ITP

D) GTP only

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25. Which of the following statements
regarding T.C.A cycle is true

A) It is amphibolic in nature

B) It contains no intermediates for GluconeogenesisIt contains no intermediates for Gluconeogenesis

C) It is an anaerobic process

D) It occurs in cytosol

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26. Which of the following reactions is unique
to gluconeogenesis

A) Oxaloacetate phosphoenol pyruvate

B) Glucose-6-phosphate Fructose-6-phosphate

C) Lactate Pyruvate

D) Phosphoenol pyruvate pyruvate

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27. Reduced glutathione functions in R.B.Cs
to

A) Produce NADPH

B) Reduce oxidizing agents such as H2O2

C) Produce NADH

D) Reduce methemoglobin to hemoglobin

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28. The free energy change, AG

A) Is directly proportional to the standard free energy change, AG

B) Is equal to zero at equilibrium

C) Is equal to –RT in keq

D) Can only be calculated when the reactants and products are present at 1mol/1 concentrations

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29. The synthesis of glucose from pyruvate
by gluconeogenesis

A) Requires the participation of biotin

B) Requires oxidation/reduction of FAD

C) Occurs exclusively in the cytosol

D) Is inhibited by elevated level of insulin

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30. The glycolysis is regulated by

A) All of these

B) Hexokinase

C) Phosphofructokinase

D) Pyruvate kinase

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31. Which of the following enzyme is not
involved in HMP shunt

A) Transketolase

B) Phosphogluconate dehydrogenase

C) Glucose-6-p-dehydrogenase

D) Glyceraldehyde-3-p dehydrogenase

Your score is

The average score is 58%

Carbohydrates Biochemistry Set 5

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