Carbohydrates Biochemistry Set 5

Test Your Knowledge and master Biochemistry

/31

Biochemistry (Carbohydrates And Carbohydrate Metabolism Set 5)

MCQ

1 / 31

The synthesis of glucose from pyruvate
by gluconeogenesis

A) Is inhibited by elevated level of insulin

B) Requires the participation of biotin

C) Requires oxidation/reduction of FAD

D) Occurs exclusively in the cytosol

2 / 31

The free energy change, AG

A) Is equal to –RT in keq

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

C) Is equal to zero at equilibrium

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

3 / 31

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

4 / 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

5 / 31

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

6 / 31

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

A) Malate dehydrogenase

B) Aconitase

C) Isocitrate dehydrogenase

D) Fumarase

7 / 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) socitrate→ Oxaloacetate

C) Succinic acid→ Fumarate

D) Citric acid→ Isocitric acid

8 / 31

Glycogen is present in all body tissues
except

A) Liver

B) Brain

C) Stomach

D) Kidney

9 / 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 exhibit ATPase activity

B) It is inhibited by oligomycin

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

D) ) It can bind molecular O2

10 / 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) Pyruvate kinase catalyses an irreversible reaction

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

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

11 / 31

Cori cycle is

A) reuse of glucose

B) Both (A) & (B

C) uptake of glycose

D) Synthesis of glucose

12 / 31

Phenylalanine is the precursor of

A) L-DOPA

B) Tyrosine

C) Throxine

D) Histamine

13 / 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

14 / 31

The reaction catalysed by phosphofructokinase

A) Uses fruitose-1-phosphate as substrate

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

C) Is inhibited by fructose 2, 6-bisphosphate

D) Is activated by high concentrations of ATP and citrate

15 / 31

Reduced glutathione functions in R.B.Cs
to

A) Produce NADPH

B) Reduce methemoglobin to hemoglobin

C) Reduce oxidizing agents such as H2O2

D) Produce NADH

16 / 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

17 / 31

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

A) 1

B) 2

C) 6

D) 4

18 / 31

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

A) Hemolytic anemia

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

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

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

19 / 31

Under standard conditions

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

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

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

D) Keq is equal to 1

20 / 31

Compared to the resting state, vigorously
contracting muscle shows

A) An increased conversion of pyruvate to lactate

B) Decreased concentration of AMP

C) A decreased NADH/NAD+ ratio

D) Decreased oxidation of pyruvate of CO2 and water

21 / 31

Glucokinase

A) Is widely distributed and occurs in most mammalian tissues

B) None of these

C) Is widely distributed in Prokaryotes

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

22 / 31

The reaction catalysed by phosphofructokinase

A) Is inhibited by fructose 2, 6-bisphosphate

B) Uses fruitose-1-phosphate as substrate

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

D) Is activated by high concentrations of ATP and citrate

23 / 31

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

A) None of these

B) GTP only

C) GTP (or) ITP

D) ITP only

24 / 31

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

A) 4

B) 6

C) 8

D) 2

25 / 31

Which of the following reactions is unique
to gluconeogenesis

A) Phosphoenol pyruvate pyruvate

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

C) Lactate Pyruvate

D) Oxaloacetate phosphoenol pyruvate

26 / 31

Phenylalanine is the precursor of

A) Tyrosine

B) Throxine

C) L-DOPA

D) Histamine

27 / 31

The glycolysis is regulated by

A) Pyruvate kinase

B) Hexokinase

C) Phosphofructokinase

D) All of these

28 / 31

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

A) CO2 and ATP

B) ATP, Protein and CO2

C) CO2

D) Protein

29 / 31

An uncoupler of oxidative phosphorylation such as dinitropheno

A) Inhibits electron transport and ATP synthesis

B) Allow electron transport to proceed without ATP synthesis

C) Inhibits electron transport without impairment of ATP synthesis

D) Specially inhibits cytochrome b

30 / 31

Which of the following enzyme is not
involved in HMP shunt

A) Glucose-6-p-dehydrogenase

B) Phosphogluconate dehydrogenase

C) Glyceraldehyde-3-p dehydrogenase

D) Transketolase

31 / 31

The conversion of pyruvate to acetyl CoA
and CO2

A) Occurs in the cytosol

B) Involves the participation of lipoic acid

C) Depends on the coenzyme biotin

D) Is reversible

Your score is

The average score is 41%

Continue Learning

Proteins Chemistry QBank

Test your understanding of carbohydrate metabolism with focused MCQs.

Carbohydrates Biochemistry Set 1

Test your understanding of key biochemistry concepts with focused MCQs.

Carbohydrates Biochemistry Flashcards

Review essential terms and concepts for quick, effective revision.