Lipid Metabolism III - IV Review Questions (3).pdf

Lipid Metabolism III & IV - Review Questions 1. A patient with hyperlipoproteinemia would be most likely to benefit from a low-carbohydrate diet if the lipoproteins that are elevated in blood are which of the following? A. Chylomicrons B. VLDL C. HDL D. LDL E. IDL 2. In humans, prostaglandins are de...

Lipid Metabolism III & IV - Review Questions 1. A patient with hyperlipoproteinemia would be most likely to benefit from a low-carbohydrate diet if the lipoproteins that are elevated in blood are which of the following? A. Chylomicrons B. VLDL C. HDL D. LDL E. IDL 2. In humans, prostaglandins are derived primarily from which one of the following? A. Glucose B. Acetyl-CoA C. Arachidonic acid D. Oleic acid E. Leukotrienes 3. Which one of the following drugs leads to the covalent modification, and inactivation, of both the COX-1 and COX-2 enzymes? A. Aspirin B. Acetaminophen (Tylenol) C. Celecoxib (Celebrex) D. Rofecoxib (Vioxx) E. Ibuprofen (Advil) 4. Dietary fatty acids are precursors for sphingolipids. Of the following, which one is formed from sphingolipids? A. Lung surfactant B. Myelin sheath C. Bile D. Arachidonic acid E. Blood lipoproteins 5. Low-dose aspirin is used as a prevention of platelet aggregation and heart attacks, whereas high dose aspirin is used as an anti-inflammatory drug. Low-dose aspirin is used to block the formation of which eicosanoid? A. Prostaglandins B. Thromboxanes C. Leukotrienes D. Lysoxins E. Epoxides 6. Infant respiratory distress syndrome is related to… A. Lungs immaturity B. major cause of neonatal morbidity and mortality. C. affects premature babies D. genetically associated condition E. All of the above 7. Fetal lung maturity can be predicted by measuring the levels of which of the following lipids. A. Lecithin B. Sphingomyelin C. Lecithin/Sphingomyelin D. Sphingomyelin/Lecithin E. None of the above 8. Sphingomyelin is made up of the following components. A. Ceramide and phosphocholine B. Sphingosine and phosphocholine C. Cerebroside and phosphoserine D. Ganglioside and phosphatidylinositol E. Ceramide and ceramide 9. Phosphoglyceride synthesis starts with the following key lipid formation. A. Ceramide B. Sphingosine C. Phosphatidic Acid D. Phosphotidylserine E. Phosphotidylethanolamine 10. Insufficient lung surfactant lead to which of the following conditions. A. collapsed alveoli B. inadequate oxygen exchange C. Infant respiratory distress syndrome D. All of the above E. None of the above 11. The statins are the major class of medications used to lower elevated serum cholesterol by initially inhibiting the major rate-limiting step of cholesterol synthesis. Which metabolite of the pathway would accumulate under conditions of taking a statin? A. Acetoacetyl-CoA B. HMG-CoA C. Mevalonate D. Squalene E. Steroid ring 12. Cholesterol, and its precursors and products, have a variety of functions within cells. Which one statement correctly describes a function of a cholesterol precursor, cholesterol itself, or a product derived from cholesterol? A. Cholesterol is hydrophilic. B. Steroid hormones are precursors of cholesterol. C. Precursors of cholesterol can be converted to vitamin D. D. Cholesterol can appear in its free unesterified form in the core of lipoprotein particles. E. Malonyl-CoA is the major precursor of cholesterol synthesis. 13. A new patient is being evaluated for cardiovascular disease. The values for his lipid panel are a total cholesterol of 400 mg/dL, an HDL reading of 35 mg/dL, and a triglyceride reading of 200 mg/dL. What would be his calculated LDL cholesterol reading? A. 165 B. 193 C. 205 D. 325 E. 365 14. Which one of the following apolipoproteins acts as a cofactor activator of the enzyme LPL? A. ApoCIII B. ApoCII C. ApoB-100 D. ApoB-48s E. ApoE 15. Which one of the following sequences places the lipoproteins in the order of most dense to least dense? A. HDL/VLDL/chylomicrons/LDL B. HDL/LDL/VLDL/chylomicrons C. LDL/chylomicrons/HDL/VLDL D. VLDL/chylomicrons/LDL/HDL E. LDL/chylomicrons/VLDL/HDL 16. Which one of the following would you expect to observe in a patient lacking microsomal triglyceride transfer protein (MTP) after eating a normal diet, in which each meal consisted of 30% fat? A. Constipation B. Elevated chylomicrons C. Steatorrhea D. Elevated VLDL E. Elevated IDL 17. Patients with elevated serum LDL levels (>120 mg/dL) are first encouraged to reduce these levels through a combination of diet and exercise. If this fails, they are often prescribed statins. The key for statin treatment reducing circulating cholesterol levels is which one of the following? A. Reduced synthesis of chylomicrons B. Increased activity of LPL C. Reduced synthesis of HDL D. Upregulation of LDL receptors E. Increased activity of CETP 18. A consequence of abetalipoproteinemia is a fatty liver (hepatic steatosis). This occurs because of which one of the following? A. Inability to produce VLDL B. Inability to produce chylomicrons C. Inability to produce HDL D. Inability to produce triglyceride E. Inability to produce LPL 19. Hormones are typically synthesized in one type of tissue, often in response to the release of a stimulatory hormone. Which one of the following correctly matches a hormone with its stimulatory hormone and its site of synthesis? A. Cortisol, ACTH, adrenal cortex B. Aldosterone, ACTH, adrenal cortex C. Testosterone, FSH, Leydig cells D. Estrogen, LH, ovarian follicle E. Progesterone, LH, ovarian follicle 20. Because the steroid nucleus cannot be degraded by the human body, excretion of bile salts in stool serves as a major route of removal of steroids from the body. Which one of the following must occur to bile salts in order for bile salts to be excreted in the stool? A. Intestinal bacteria deconjugate bile salts. B. Intestinal bacteria conjugate bile salts. C. ATP and coenzyme Q conjugate bile salts. D. ATP and coenzyme A deconjugate bile salts. E. Enterohepatic circulation occurs at 100% efficiency. 21. Which of the following lipids belongs to eicosanoids. A. Prostaglandins B. Thromboxanes C. leukotrienes D. All of the above E. None of the above 22. Which of the following functions are the major roles of eicosanoids. A. Inflammatory responses B. Vascular contraction/relaxation C. Bronchial dilatation/constriction D. All of the above E. None of the above 23. Which one of the following phospholipid metabolite act as second messenger? A. Sphingomyelin B. IP3 C. Diacylglycerol D. LDL E. Cholesterol 24. Which of the following lysosomal storage disease (spingolipidosis) is not an autosomal recessive disease. A. Tay-sachs disease B. Fabrys disease C. Niemann-pick disease D. Gaucher disease E. none of the above 25. Hexaminadase A enzyme deficiency cause which of the following disease. A. Tay-sachs disease B. Fabrys disease C. Niemann-pick disease D. Gaucher disease E. none of the above 26. VLDL synthesis takes place in which of the following organs/tissues. A. Blood B. Spleen C. Kidney D. Liver E. Brain 27. HDL synthesis and maturation takes place in which of the following organs/tissues. A. Blood (circulation) B. Spleen C. Kidney D. Liver E. A and D 28. Phospholipid degradation is catalyzed by which of the following enzymes. A. Hexokinase B. HMG-CoA synthase C. Phospholipases D. COX1 E. Glycerokinase 29. Which one of the following enzyme regulate cholesterol synthesis. A. HMG-CoA synthase B. HMG-CoA reductase C. Squalene monooxygenase D. acyl coenzyme A-cholesterol acyltransferase (ACAT) E. 7α-hydroxylase 30. Which of the following is not a function of cholesterol. A. Vitamin D synthesis B. Steroid hormone synthesis C. Bile acids and bile salt formation D. Structural component of cell membrane E. Eicosanoid formation Answers 1. The answer is B. 2. The answer is C. 3. The answer is A. 4. The answer is B. 5. The answer is B. 6. The answer is E. 7. The answer is C. 8. The answer is A. 9. The answer is C. 10. The answer is D. 11. The answer is B. 12. The answer is C. 13. The answer is D. Total cholesterol is equal to the lipoproteins that carry it because cholesterol cannot freely float in blood serum. The total cholesterol would then be composed of the cholesterol content of HDL, VLDL, and LDL. Under fasting conditions, taking the triglyceride concentration and dividing it by 5 can estimate the cholesterol content of VLDL. Thus, for this patient, the HDL is 35 mg/dL, and the VLDL is 40 mg/dL. The total cholesterol is 400 mg/dL, indicating that the calculated LDL cholesterol is 400 − 75, or 325 mg/dL. 14. The answer is B. 15. The answer is B. 16. The answer is C. 17. The answer is D. 18. The answer is A. 19. The answer is A. 20. The answer is A. 21. The answer is D. 22. The answer is D. 23. The answer is B. 24. The answer is B. 25. The answer is A. 26. The answer is D. 27. The answer is E. 28. The answer is C. 29. The answer is B. 30. The answer is E.