Biochemistry- multiple choice questions (a quick revision of important topics)

1) The energy yield during the conversion of Succinate to Fumarate is-

a) 2ATP

b) 1ATP

c) 3ATP

d) No ATP

2)  Which of the following occurs in non-shivering thermogenesis?

a) Glucose is oxidized to lactate

b) Fatty acids uncouple oxidative phosphorylation

c) ATP is spent on heat production

d) Glycogen is excessively degraded

3) Which vitamin is required for almost all aspects of protein and amino acid metabolism?

a) Vitamin B6

b) Vitamin B12

c) Vitamin C

d) Vitamin B3

4) Which one of the following transfer acyl groups?   

a) Thiamine pyrophosphate

b) Lipoamide

c) NADH

d) FADH2

5) Homocystinuria is due to the deficiency of-

a)Vitamin B12

b) B6

c) Folic acid

d) All of the above.

6) Which out of the followings is not a substrate-specific enzyme?
a) Glucokinase

b) Fructokinase

c) Hexokinase

d) Phosphofructokinase

7)  A 67- year-old army officer in good health previously presented with sudden pain in the great toe. Serum uric acid was high, and a diagnosis of gouty arthritis was made. He was advised bed rest, pain killers, and Allopurinol. What is the mechanism of action of Allopurinol in lowering serum uric acid levels?

a) Suicidal inhibition

b) Non-competitive inhibition

c) Allosteric inhibition

d) Feedback inhibition

8) The mother of a malnourished child has been instructed to include a complete protein in her child’s diet. Which of the following proteins should be recommended?

a) Pulses

b) Wheat

c) Soy Protein

d) Milk

9) Which of the following peptides is cyclic in structure?

a) Glutathione

b) Gramicidin-S

c) Met encephalin

d) Leuencephalin

10) All the below-mentioned proteins are metalloproteins except-

a) Carbonic anhydrase

b) Xanthine oxidase

c) Lactate dehydrogenase

d) Superoxide dismutase

11)  Which of the following supplies the two carbon units that are added to the elongation of the fatty acid chain?

a) Acetyl co A

b) Malonyl co A

c) β- Keto acyl co A

d) Glucose.

12) Glucose can be converted to glycerol-3-P through which of the following intermediates?

a) Glycerol

b) Dihydroxy acetone phosphate

c) Acetyl co A

d) Pyruvate

13) The complete oxidation of odd chain fatty acid produces which of the followings?

a) Acetyl co A only

b) Acetyl co A and Propionyl co A

c) Butyryl co A

d) Palmitoyl co A

14) In which of the following porphyrias cutaneous hypersensitivity is not observed?

a) Variegate Porphyria

b) Acute intermittent Porphyria

c) Congenital Erythropoietic Porphyria

d) Hereditary Coproporphyria

15) All are correct about the pyruvate dehydrogenase complex except one-

a) The formation of acetyl CoA from pyruvate is an irreversible step

b) Pyruvate dehydrogenase is switched off when the energy charge is high

c) Phosphorylation switches off the activity of the complex.

d) Pyruvate and ADP (a signal of low energy charge) inhibit the complex.

16) Which of the following is a cofactor in the reaction catalyzed by glyceraldehyde 3-phosphate dehydrogenase?

a) ATP

b) Cu²⁺

c) Heme

d) NAD⁺

17) The citric acid cycle is inhibited by which of the following?

a) Fluoroacetate

b) Aerobic conditions

c) Malic acid

d) Fluorouracil

18) Which of the following fatty acids is a precursor of series -1 Eicosanoids?

a) Linoleic acid

b) Arachidonic acid

c) Eicosapentaenoic acid

d) Linolenic acid

19) Cholesterol is a precursor of all except-

a)Bile salts,

b)Bilirubin

c) Steroids

d) vitamin D

20) Polyamines are formed from which of the following amino acids?

a) Citrulline

b) Ornithine

c) Arginine

d) Argininosuccinic acid.

 

Key to answers- 1)-a,2)-b,3)-a, 4)-b,5)-d,6)-c,7)-a,8)-d,9)-b,10)-c,11)-b,12)-b,13)-b,14)-b,15)-d,16)-d,17)-a,18)-d,19)-b,20)-b