Carbohydrates Biochemistry Set 5

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/31

Biochemistry (Carbohydrates And Carbohydrate Metabolism Set 5)

MCQ

1 / 31

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

A) Lose (or) gain electrons

B) Lose electrons

C) Gain electrons

D) Lose and gain electrons

2 / 31

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

A) Aconitase

B) Isocitrate dehydrogenase

C) Fumarase

D) Malate dehydrogenase

3 / 31

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

A) GTP only

B) GTP (or) ITP

C) None of these

D) ITP only

4 / 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

5 / 31

The synthesis of glucose from pyruvate
by gluconeogenesis

A) Occurs exclusively in the cytosol

B) Requires the participation of biotin

C) Requires oxidation/reduction of FAD

D) Is inhibited by elevated level of insulin

6 / 31

Phenylalanine is the precursor of

A) Histamine

B) Tyrosine

C) L-DOPA

D) Throxine

7 / 31

The reaction catalysed by phosphofructokinase

A) Is activated by high concentrations of ATP and citrate

B) Uses fruitose-1-phosphate as substrate

C) Is inhibited by fructose 2, 6-bisphosphate

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

8 / 31

Which of the following reactions is unique
to gluconeogenesis

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

B) Oxaloacetate phosphoenol pyruvate

C) Lactate Pyruvate

D) Phosphoenol pyruvate pyruvate

9 / 31

The free energy change, AG

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

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

C) Is equal to zero at equilibrium

D) Is equal to –RT in keq

10 / 31

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

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

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

C) Hemolytic anemia

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

11 / 31

The reaction catalysed by phosphofructokinase

A) Is inhibited by fructose 2, 6-bisphosphate

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

C) Uses fruitose-1-phosphate as substrate

D) Is activated by high concentrations of ATP and citrate

12 / 31

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

C) Pyruvate kinase catalyses an irreversible reaction

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

13 / 31

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

A) ) It can bind molecular O2

B) It is inhibited by oligomycin

C) It can exhibit ATPase activity

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

14 / 31

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

A) It occurs in cytosol

B) It is amphibolic in nature

C) It is an anaerobic process

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

15 / 31

The glycolysis is regulated by

A) Phosphofructokinase

B) All of these

C) Pyruvate kinase

D) Hexokinase

16 / 31

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

17 / 31

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

18 / 31

Phenylalanine is the precursor of

A) Histamine

B) Throxine

C) L-DOPA

D) Tyrosine

19 / 31

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

A) Protein

B) CO2 and ATP

C) CO2

D) ATP, Protein and CO2

20 / 31

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

A) 6

B) 2

C) 4

D) 8

21 / 31

Reduced glutathione functions in R.B.Cs
to

A) Reduce oxidizing agents such as H2O2

B) Produce NADPH

C) Produce NADH

D) Reduce methemoglobin to hemoglobin

22 / 31

Glycogen is present in all body tissues
except

A) Liver

B) Kidney

C) Brain

D) Stomach

23 / 31

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) Succinylcat→ Succinic acid

B) Succinic acid→ Fumarate

C) socitrate→ Oxaloacetate

D) Citric acid→ Isocitric acid

24 / 31

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

25 / 31

The conversion of pyruvate to acetyl CoA
and CO2

A) Occurs in the cytosol

B) Is reversible

C) Involves the participation of lipoic acid

D) Depends on the coenzyme biotin

26 / 31

Cori cycle is

A) reuse of glucose

B) uptake of glycose

C) Both (A) & (B

D) Synthesis of glucose

27 / 31

Compared to the resting state, vigorously
contracting muscle shows

A) A decreased NADH/NAD+ ratio

B) An increased conversion of pyruvate to lactate

C) Decreased concentration of AMP

D) Decreased oxidation of pyruvate of CO2 and water

28 / 31

An uncoupler of oxidative phosphorylation such as dinitropheno

A) Inhibits electron transport and ATP synthesis

B) Specially inhibits cytochrome b

C) Inhibits electron transport without impairment of ATP synthesis

D) Allow electron transport to proceed without ATP synthesis

29 / 31

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

A) Lactate

B) Glycerol

C) Acetyl CoA

D) α-ketoglutarate

30 / 31

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

31 / 31

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

A) 1

B) 2

C) 4

D) 6

Your score is

The average score is 41%

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