Lipids- Multiple-choice questions-set-3

1. Which of the following are the ketone bodies?

a) Acetyl CoA and Propionyl CoA

b) Lecithin and Lysolecithin

c) Acetoacetate and Beta-hydroxybutyrate

d) Pyruvate and lactate

e) Succinyl CoA and succinate

2. The enzyme ‘Thiolase’ catalyzes the conversion of:

a) 2 Acetyl CoA to Acetoacetyl CoA

b) Acetyl CoA to Malonyl CoA

c) Fatty acid to Fatty Acyl CoA

d) Succinyl CoA to succinate

e) Propionyl CoA to D- Methyl malonyl CoA

3. In contrast to secondary bile salts, which of the following is characteristic of primary bile salts?

a) Are hydroxylated at carbon 7

b) Have an oxidized side chain

c) Form CoA derivatives

d) Can be conjugated to Glycine or Taurine

e) Are reabsorbed in the intestine

4. Which of the following statements best describes the fatty acid synthase complex?

a) Is a dimer of dissimilar subunits

b) is composed of 7 different proteins

c) Dissociates into eight different proteins

d) Catalyzes eight different enzymatic steps

e) Is composed of covalently linked enzymes

5. The end product of fatty acid synthesis in mammals is –

a) Arachidonic acid

b) Linoleic acid

c) Stearic acid

d) Palmitic acid

e) Erucic acid

6. Which enzyme often malfunctions in diseases associated with the symptoms of high blood triglyceride levels and Steatorrhea?

a) Phospholipase D

b) Lipoprotein lipase

c) Thiokinase

d) Acetyl CoA carboxylase

e) Pancreatic lipase

7. Which enzyme is an allosteric regulator of another enzyme on the list?

a) Acetyl CoA carboxylase

b) Pancreatic lipase

c) Carnitine acyl transferase-1

d) Acetyl transacylase

e) Keto acyl synthase

8. A newborn has severe respiratory problems. Over the next few days, it is observed that the baby has severe muscle problems, demonstrates little development, and has neurological problems. A liver biopsy reveals a very low level of acetyl CoA carboxylase but normal levels of the enzymes of glycolysis and gluconeogenesis, the citric acid cycle, and the pentose phosphate pathway. What is the most likely cause of an infant’s respiratory problems?

a) Low level of phosphatidylcholine

b) Biotin deficiency

c) Ketoacidosis

d) High level of citrate

e) Glycogen depletion

9. In cystic fibrosis, the pancreatic ducts become obstructed by viscous mucus. Consequently, digestion of which of the following substances would be most impaired?

a) Starch

b) Glycogen

c) Cellulose

d) Lipids

e) Maltose

10. Insulin promotes which of the following?

a) Transport of glucose into cells

b) Conversion of Triacyl glycerol to diacylglycerol

c) Fatty acid oxidation

d) Decreased activity of lipoprotein lipase

e) Increased blood glucose level

11.Dicarboxylic aciduria is a defect associated with impaired-

a) Alpha oxidation of fatty acids

b) Beta oxidation of fatty acids

c) Fatty acid synthesis

d) Omega oxidation of fatty acids

e) de novo cholesterol synthesis

12. In alpha oxidation which of the following products is released?

a) CoA

b) CO₂

c) H₂O

d) Acetyl CoA

e) Malonyl CoA

13. A 2 year -old boy has been diagnosed with Zellweger syndrome, a disorder caused by malformation of peroxisomes. The oxidation of which of the following fatty acids is impaired in this defect?

a) Palmitic acid

b) Unsaturated fatty acids

c) Very long-chain fatty acids

d) Branched hail fatty acids

e) Cyclic fatty acids

14. A 15-year-old female has been diagnosed with anorexia nervosa. In this patient breakdown of fatty acids is required to provide energy. Prior to fatty acid oxidation, activation of fatty acid takes place in the cytosol. Which of the following is the product of fatty acid activation?

a) ATP

b) CoA

c) Fatty acyl CoA

d) Carnitine

e) Malonyl CoA

15. Tangier disease is a disease of cholesterol transport. The first case was identified in a patient who lived on the island of Tangier and who had characteristic orange-colored tonsils, a very low HDL, and an enlarged liver and spleen. Due to mutation in a transport protein, cholesterol cannot properly exit the cell to bind to apo A. Which of the following is the most crucial risk factor for such patients due to a deceased level of HDL?

a) Diabetes mellitus

b) Atherosclerosis

c) Cataract

d) Ketosis

e) Fatty liver

16. A 40 -year-old man presents with severe pain in his legs upon walking. He is diagnosed with atherosclerotic plaques in the arteries of his legs. High levels of cholesterol and LDL contribute to the formation of atherosclerosis. The oxidized form of LDL triggers the process of atherosclerosis. Which of the following is an essential structural component of LDL?

a) Apo B48

b) Apo B 100

c) Apo A

d) Apo C

e) Apo E

17. A 30 -year-old man has been diagnosed with familial hypercholesterolemia, a disorder caused by a deficiency of LDL receptors. Which of the following statements best describes the status of these patients?

a) Serum cholesterol decreases

b) HDL releases excessive cholesterol

c) Cholesterol synthesis by hepatocytes is increased

d) Number of LDL receptors on the surface of hepatocytes increase

e) After binding to LDL receptors, LDL is rapidly degraded

18. A 25-year-old woman presents with a low red blood cell count, corneal opacities, and kidney insufficiency. In addition, she is diagnosed with Lecithin: Cholesterol acyl transferase(LCAT) deficiency. Which of the following is LCAT involved in?

a) Converting cholesterol to cholesteryl ester

b) Transfer of cholesterol to other lipoproteins

c)  Degradation of HDL in liver

d) Degradation of chylomicrons

e) Decreased uptake of cholesterol by hepatocytes

19. A 34-year-old female has been diagnosed with type 1 hyperlipidemia. Which of the following lipoprotein concentration is elevated in such a disorder?

a) VLDL

b) IDL

c) LDL

d) Chylomicrons

e) All of the above

20. The abundance of which of the following inhibits beta-oxidation of fatty acids?

a) ATP

b) Long-chain fatty acids

c) Malonyl CoA

d) Citrate

e) Acetyl CoA

Key to answers

1) – c

2)- a

3)- a

4)-e

5)- d

6)- e

7)- a

8)- a

9)- d

10)- a

11)- b

12)- b

13)- c

14)- c

15)-b

16)- b

17)- c

18)- a

19)- d

20)- c