Lipid Metabolism: Key Processes & Diseases

Lipid Metabolism

1. In the human body, synthesis of fatty acids occurs in:

c. Adipocytes

2. The critical process of emulsification of dietary lipids occurs:

b. In the duodenum

3. Cholesteryl esters are hydrolyzed by:

e. Answers C and D are correct

4. The role of bile in the digestion of triglycerides is:

a. Emulsification of fat drops to droplets

5. Beta-oxidation of very-long-chain fatty acids (VLCFA) occurs in:

e. There is no correct answer

6. Fatty acids are NOT:

c. Associated with proteins in membranes

7. The immediate precursor of prostaglandins is:

d. Arachidonic acid

8. During the degradation of TAG:

a. Procolipase is activated by trypsin

9. Select the correct answer:

a. During the digestion of dietary lipids, cholecystokinin decreases gastric motility and stimulates the secretion of bile.

10. Mark true (T) or false (F) about Tay-Sachs disease:

a. Accumulation of gangliosides

T/F

b. Muscular weakness and blindness

T/F

c. Skeletal deformities

T/F

11. Mark true (T) or false (F) about lipoproteins:

a. VLDL deliver cholesterol to the liver

T/F

b. LDL are composed of low TAG and low cholesterol

T/F

c. Chylomicrons deliver dietary triacylglycerol to the liver

T/F

12. Mark true (T) or false (F) about plasma lipoproteins:

a. Chylomicrons are the lipoproteins with the highest percentage of proteins

T/F

b. LDLs are denser than VLDL

T/F

c. HDLs are the lipoproteins with the lowest percentage of protein

T/F

13. Mark the true answer about hypertriacylglycerolemia:

a. Is caused by a deficiency of lipoprotein lipase

14. You prescribe ibuprofen to help reduce your patient’s inflammation. Which of the following pathways is blocked as an anti-inflammatory mechanism of action of nonsteroidal anti-inflammatory drugs?

a. Prostaglandin synthesis

15. Niemann-Pick disease (an autosomal recessive disease) is caused by:

c. Deficiency of sphingomyelinase

16. A model presents the structure of:

b. Cholesterol

17. Colipase (secreted by the pancreas) is secreted as a zymogen – procolipase, which is activated in the intestine by:

c. Trypsin

18. Lipogenesis is regulated at the stage of acetyl CoA carboxylase:

e. There is no correct answer

19. Oxidation of LDL is (stimulated/inhibited) by:

a. Inhibited by ascorbic acid

b. Stimulated by hydrogen peroxide

c. Inhibited by Vitamin E

20. Essential fatty acid (linoleic and α-linolenic) deficiency can result in:

b. A scaly dermatitis, as well as visual and neurologic abnormalities

21. A palmitoyl-ACP is formed as a result of:

a. Five-cycle repetition of fatty acid synthesis

22. The most common compounds of bile acids are:

c. Cholic acid and chenodeoxycholic acid

23. Mark true (T) and false (F) for the following sentences:

Carnitine can be obtained from the diet, where it is found primarily in meat products

T/F

Carnitine can be synthesized from the amino acids lysine and methionine

T/F

Carnitine can be synthesized by an enzymatic pathway found in the liver and kidney

T/F

Carnitine deficiency can be caused by pregnancy, severe infections, burns, trauma, or hemodialysis

T/F

24. Describe the missing compound names in the scheme of fatty acid β-oxidation:

A

a. 3-L-hydroxyacyl-CoA

b. β-ketoacyl-CoA

c. Acetyl-CoA

d. Fatty acyl-CoA

25. Two molecules of phosphatidic acid (PA) esterified through their phosphate groups to an additional molecule of glycerol is called:

a. Cardiolipin

26. Pancreatic secretion of the hydrolytic enzymes that degrade dietary lipids in the small intestine is hormonally controlled by:

c. A small peptide hormone – cholecystokinin (CCK)