Carbohydrates Biochemistry Set 5

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Biochemistry (Carbohydrates And Carbohydrate Metabolism Set 5)

MCQ

1 / 31

Cori cycle is

A) Synthesis of glucose

B) reuse of glucose

C) uptake of glycose

D) Both (A) & (B

2 / 31

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

A) 1

B) 4

C) 2

D) 6

3 / 31

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

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

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

C) Hemolytic anemia

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

4 / 31

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

A) Electrons

B) All of these

C) Uncouplers

D) Protons

5 / 31

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

A) 2

B) 8

C) 4

D) 6

6 / 31

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

A) Lose electrons

B) Gain electrons

C) Lose (or) gain electrons

D) Lose and gain electrons

7 / 31

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

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

B) It occurs in cytosol

C) It is an anaerobic process

D) It is amphibolic in nature

8 / 31

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

9 / 31

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

A) Aconitase

B) Isocitrate dehydrogenase

C) Malate dehydrogenase

D) Fumarase

10 / 31

Glycogen is present in all body tissues
except

A) Stomach

B) Kidney

C) Liver

D) Brain

11 / 31

Under standard conditions

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

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

C) Keq is equal to 1

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

12 / 31

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

13 / 31

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

A) CO2 and ATP

B) ATP, Protein and CO2

C) Protein

D) CO2

14 / 31

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

15 / 31

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

A) Glycerol

B) Acetyl CoA

C) α-ketoglutarate

D) Lactate

16 / 31

The reaction catalysed by phosphofructokinase

A) Is inhibited by fructose 2, 6-bisphosphate

B) Is activated by high concentrations of ATP and citrate

C) Uses fruitose-1-phosphate as substrate

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

17 / 31

Reduced glutathione functions in R.B.Cs
to

A) Produce NADPH

B) Reduce methemoglobin to hemoglobin

C) Produce NADH

D) Reduce oxidizing agents such as H2O2

18 / 31

Phenylalanine is the precursor of

A) Tyrosine

B) Histamine

C) L-DOPA

D) Throxine

19 / 31

The reaction catalysed by phosphofructokinase

A) Is inhibited by fructose 2, 6-bisphosphate

B) Is activated by high concentrations of ATP and citrate

C) Uses fruitose-1-phosphate as substrate

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

20 / 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 can exhibit ATPase activity

C) It is inhibited by oligomycin

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

21 / 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

22 / 31

Phenylalanine is the precursor of

A) Throxine

B) Tyrosine

C) L-DOPA

D) Histamine

23 / 31

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

24 / 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

25 / 31

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

26 / 31

The glycolysis is regulated by

A) Pyruvate kinase

B) Hexokinase

C) All of these

D) Phosphofructokinase

27 / 31

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

A) GTP (or) ITP

B) GTP only

C) None of these

D) ITP only

28 / 31

The synthesis of glucose from pyruvate
by gluconeogenesis

A) Is inhibited by elevated level of insulin

B) Requires oxidation/reduction of FAD

C) Requires the participation of biotin

D) Occurs exclusively in the cytosol

29 / 31

The conversion of pyruvate to acetyl CoA
and CO2

A) Is reversible

B) Depends on the coenzyme biotin

C) Involves the participation of lipoic acid

D) Occurs in the cytosol

30 / 31

Which of the following enzyme is not
involved in HMP shunt

A) Phosphogluconate dehydrogenase

B) Glucose-6-p-dehydrogenase

C) Transketolase

D) Glyceraldehyde-3-p dehydrogenase

31 / 31

The free energy change, AG

A) Is equal to –RT in keq

B) Is equal to zero at equilibrium

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

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

Your score is

The average score is 41%

Carbohydrates Biochemistry Set 5

Carbohydrates Biochemistry Set 5

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