Lipid Metabolism- Multiple choice questions- set-1

1) Which of the following is the best marker for the diagnosis of Acute pancreatitis?

a) Lactase

b) Amylase

c) Cholesteryl esterase

d) Υ- Glutamyl trans peptidase

e) Sucrase

2) A gall stone that blocked the upper part of the bile duct would cause an –

a) Increased formation of chylomicron

b) Increased recycling of bile salts

c) Increased excretion of bile salts

d) Decreased excretion of fats in the feces

e) Incomplete lipid digestion and absorption

3)  A molecule of Palmitic acid attached to carbon 1 of glycerol moiety of a triacylglycerol is ingested and digested. Which of the following molecular complexes in the blood carries the palmitate residue from the lumen of the gut to the surface of the gut epithelial cell?

a) VLDL

b) LDL

c) IDL

d) HDL

e) Bile salt

4) – Which of the following supplies all the carbon atoms that are needed for de novo synthesis of cholesterol?

a) Glucose

b) Acetyl co A

c) Malonyl co A

d) Succinyl co A

e) Citrate

5) – Which of the following is not needed for the de novo synthesis of fatty acids?

a) NADPH

b) Acetyl co A

c) Bicarbonate

d) ATP

e) Folic acid

6) Glycerol produced from hydrolysis of triglycerides in adipose tissue is a waste product, since it has to be in glycerol-3-P form and the enzyme for phosphorylation, glycerol kinase is absent in the adipose tissue. Glycerol -3-P can still be produced in the adipose tissue through interconversion of one of the glycolytic intermediate. Which of the following glycolytic intermediates can be used for the synthesis of glycerol-3-P?

a) Phospho enol pyruvate

b) 1, 3 Bisphosphoglycerate

c) Dihydroxyacetone phosphate

d) Fructose 1, 6 bisphosphate

e) 2, phosphoglycerate

7) Which of the following enzymes is required for releasing the newly synthesized fatty acid from the fatty acid synthase complex?

a) Thiolase

b) Thiophorase

c) Thioesterase

d) Thiokinase

e) Hydratase

8) Which of the following is the key regulatory enzyme of fatty acid synthesis?

a) ATP citrate lyase

b) Keto acyl synthase

c) Acetyl transacylase

d) Acetyl co A carboxylase

e) Thiolase

9) The “microsomal system “elongates saturated and unsaturated fatty acyl-CoAs (from C₁₀ upward) by two carbons, using-

a) Malonyl co A

b) Acetyl co A

c) Succinate

d) Pyruvate

e) Citrate

10) Which of the following is a break down product of odd chain fatty acids?

a) Acetyl co A only

b) Acetyl co A and Butyryl co A

c) Acetyl co A and Propionyl co A

d) Propionyl co A only

e) Butyryl co A only

11) Lipogenesis is increased when sucrose is fed instead of glucose because-

a) Sucrose is digested and absorbed rapidly

b) Sucrose metabolism causes release of insulin

c) Fructose, the hydrolytic product activates acetyl co A carboxylase

d) Fructose bypasses the phosphofructokinase control point in glycolysis and floods the pathway

e) All of the above

12) An obese, 40- year-old woman, who recently underwent gastric bypass surgery, presents with severe vomiting due to rapid intake of large quantities of food, which must be avoided after gastric bypass surgery. She had successfully lost 10 pounds over the last month after the surgery due to mobilization of fat stores to provide acetyl co A and energy. When Stearic acid is oxidized, how many Acetyl co A are produced?

a) 1

b) 8

c) 9

d) 2

e) 10

13) A 4 month -old infant presents with a seizure. His mother reports that her infant has been irritable and lethargic over the past several days. The infant is found to have a profoundly low serum glucose and ketone body level. The infant is diagnosed with medium chain acyl co A dehydrogenase deficiency. What is the biochemical basis of infant’s symptoms?

a) Beta oxidation of fatty acid is impaired

b) Fatty acid synthesis is impaired

c) Adipolysis is inhibited

d) TCA cycle is inhibited

e) Pyruvate to acetyl co A conversion is inhibited

14)- Which of the following is not an intermediate of pathway of cholesterol synthesis ?

a) Mevalonate

b) Squalene

c) Lanosterol

d) Desmosterol

e) 7- dehydro cholesterol

15) A 45 -year-old female presents with pain in the right hypochondrium radiating towards shoulder and back. She is diagnosed with acute cholecystitis (inflammation of the gall bladder).The gall stones can obstruct the gall bladder, leading to an inadequate concentration of bile salts in the intestine. Which of the following statements best describes the bile salts?

a) Squalene and Lanosterol are examples of primary bile salts

b) Bile salts are required for transportation of lipids from intestine to liver

c) 95% of the bile salts are excreted in the feces per day

d) They are required for digestion and absorption of lipids

e) Bile salts are synthesized from glycine and taurine.

16) Which of the following apo proteins is an activator of LCAT?

a) Apo A

b) Apo B

c) Apo C II

d) Apo A- I

e) Apo E

17) In Abetalipoproteinemia (a rare disease), lipoproteins containing apo B are not formed and lipid droplets accumulate in the intestine and liver. Which of the following lipoproteins does not contain Apo B protein?

a) LDL

b) IDL

c) HDL

d) Chylomicrons

e) Lp (a)

18) Which of the following statements best describes cholesterol ester transfer protein (CETP)?

a) It converts cholesterol from LDL to cholesterol esters

b) It is the major protein of Chylomicrons

c) It exchanges cholesterol esters from HDL for other lipids

d) It acts as a ligand for LDL receptors

e) It transfers cholesteryl esters from peripheral tissues to HDL

19) An infant is born prematurely at 28 weeks and has developed increasing difficulty in breathing. His skin starts to turn blue from lack of oxygen(cyanosis). He is diagnosed with Respiratory distress syndrome due to deficiency of lung surfactant. Which of the following is the phospholipid of primary importance in surfactant?

a) Dipalmitoyl phosphatidylcholine

b) Dipalmitoyl phosphatidylethanolamine

c) Dipalmitoyl phosphoglyceride

d) Dipalmitoyl phosphatidyl Inositol

e) Dipalmitoyl phosphatidylserine

20) A male infant is born with ambiguous genitalia (from lack of androgens such as testosterone) and several salt wasting (due to lack of aldosterone). He is diagnosed with a 3-β-hydroxylase deficiency. Testosterone is produced from which of the following compounds?

a) Arachidonic acid

b) Linolenic acid

c) Glucose

d) Cholesterol

e) Acetyl co A

21) A 20- year-old woman has a myocardial infarct and is given an Aspirin to chew. Taking aspirin has been shown to be cardioprotective in myocardial infarction. Aspirin is a non-steroidal anti-inflammatory drug that inhibits cyclooxygenase enzyme (COX). Cyclo-oxygenase is required for the production of which of these?

a)Thromboxane from Arachidonic acid

b) Leukotrienes from Arachidonic acid

c) Arachidonic acid from Linoleic acid

d) Release of Arachidonic acid from membrane Phospholipids

e) Hydroperoxy eicosa tetra enoic acid (HPETEs) from Arachidonic acid

 

Key to answers

1) – b

2) – e

3)-e

4) – b

5) – e

6)- c

7)-c

8) – d

9) – a

10) – c

11)-d

12) – c

13) – a

14)-e

15) – d

16)-d

17)-c

18)-c

19) -a

20) -d

21)-a