Carbohydrates Biochemistry Set 5

/31

Biochemistry (Carbohydrates And Carbohydrate Metabolism Set 5)

MCQ

1 / 31

1. 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

2 / 31

2. The reaction catalysed by phosphofructokinase

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

B) Uses fruitose-1-phosphate as substrate

C) Is inhibited by fructose 2, 6-bisphosphate

D) Is activated by high concentrations of ATP and citrate

3 / 31

3. The glycolysis is regulated by

A) All of these

B) Phosphofructokinase

C) Hexokinase

D) Pyruvate kinase

4 / 31

4. The conversion of pyruvate to acetyl CoA
and CO2

A) Involves the participation of lipoic acid

B) Occurs in the cytosol

C) Depends on the coenzyme biotin

D) Is reversible

5 / 31

5. 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) socitrate→ Oxaloacetate

C) Succinic acid→ Fumarate

D) Succinylcat→ Succinic acid

6 / 31

6. Which of the following reactions is unique
to gluconeogenesis

A) Glucose-6-phosphate Fructose-6-phosphate

B) Oxaloacetate phosphoenol pyruvate

C) Phosphoenol pyruvate pyruvate

D) Lactate Pyruvate

7 / 31

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

A) Fumarase

B) Isocitrate dehydrogenase

C) Aconitase

D) Malate dehydrogenase

8 / 31

8. The synthesis of glucose from pyruvate
by gluconeogenesis

A) Requires the participation of biotin

B) Occurs exclusively in the cytosol

C) Is inhibited by elevated level of insulin

D) Requires oxidation/reduction of FAD

9 / 31

9. 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 inhibited by oligomycin

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

C) ) It can bind molecular O2

D) It can exhibit ATPase activity

10 / 31

10. Glucokinase

A) Is widely distributed and occurs in most mammalian tissues

B) Is widely distributed in Prokaryotes

C) None of these

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

11 / 31

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

A) It occurs in cytosol

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

C) It is an anaerobic process

D) It is amphibolic in nature

12 / 31

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

A) ATP, Protein and CO2

B) CO2 and ATP

C) Protein

D) CO2

13 / 31

13. Phenylalanine is the precursor of

A) Tyrosine

B) Throxine

C) L-DOPA

D) Histamine

14 / 31

14. Under standard conditions

A) Keq is equal to 1

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

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

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

15 / 31

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

A) 1

B) 2

C) 4

D) 6

16 / 31

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

A) α-ketoglutarate

B) Glycerol

C) Lactate

D) Acetyl CoA

17 / 31

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

A) Glyceraldehyde-3-p dehydrogenase

B) Glucose-6-p-dehydrogenase

C) Phosphogluconate dehydrogenase

D) Transketolase

18 / 31

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

A) Produce NADPH

B) Reduce oxidizing agents such as H2O2

C) Reduce methemoglobin to hemoglobin

D) Produce NADH

19 / 31

19. The reaction catalysed by phosphofructokinase

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

B) Is inhibited by fructose 2, 6-bisphosphate

C) Uses fruitose-1-phosphate as substrate

D) Is activated by high concentrations of ATP and citrate

20 / 31

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

A) 8

B) 6

C) 4

D) 2

21 / 31

21. Cori cycle is

A) uptake of glycose

B) reuse of glucose

C) Both (A) & (B

D) Synthesis of glucose

22 / 31

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

A) An increased conversion of pyruvate to lactate

B) A decreased NADH/NAD+ ratio

C) Decreased concentration of AMP

D) Decreased oxidation of pyruvate of CO2 and water

23 / 31

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

A) Produce NADH

B) Produce NADPH

C) Reduce methemoglobin to hemoglobin

D) Reduce oxidizing agents such as H2O2

24 / 31

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

A) GTP (or) ITP

B) ITP only

C) GTP only

D) None of these

25 / 31

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

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

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

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

D) Hemolytic anemia

26 / 31

26. Glycogen is present in all body tissues
except

A) Stomach

B) Kidney

C) Brain

D) Liver

27 / 31

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

A) Protons

B) Electrons

C) All of these

D) Uncouplers

28 / 31

28. Phenylalanine is the precursor of

A) Tyrosine

B) Throxine

C) Histamine

D) L-DOPA

29 / 31

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

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

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

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

D) Pyruvate kinase catalyses an irreversible reaction

30 / 31

30. The free energy change, AG

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

B) Is equal to zero at equilibrium

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

D) Is equal to –RT in keq

31 / 31

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

A) Lose and gain electrons

B) Lose (or) gain electrons

C) Lose electrons

D) Gain electrons

Your score is

The average score is 41%

Carbohydrates Biochemistry Set 5

Follow Us on Social Media