Biological role of lipids MCQs With Answer

Biological role of lipids MCQs With Answer is an essential review for B. Pharm students preparing for pharmacology, biochemistry, and pharmaceutical analysis. This concise, SEO-friendly introduction covers lipid classification, fatty acids, phospholipids, cholesterol, lipoproteins, eicosanoids, lipid metabolism and membrane functions. Emphasis on lipid digestion, transport, signaling molecules (prostaglandins, leukotrienes), and clinical aspects such as dyslipidemia and lipid-based drug delivery helps build core understanding. These targeted MCQs with answers reinforce concepts crucial for exams and practical applications in pharmacy. Keywords: Biological role of lipids MCQs With Answer, lipids, lipid metabolism, lipoproteins, fatty acids, cholesterol, B. Pharm. Now let’s test your knowledge with 50 MCQs on this topic.

Q1. Which lipid class is the main structural component of cellular membranes?

  • Triacylglycerols
  • Phospholipids
  • Cholesterol esters
  • Free fatty acids

Correct Answer: Phospholipids

Q2. Which fatty acid type increases membrane fluidity at physiological temperature?

  • Saturated fatty acids
  • Trans fatty acids
  • Monounsaturated fatty acids
  • Polyunsaturated fatty acids

Correct Answer: Polyunsaturated fatty acids

Q3. Which enzyme catalyzes the rate-limiting step in cholesterol biosynthesis?

  • Acetyl-CoA carboxylase
  • HMG-CoA reductase
  • Fatty acid synthase
  • Cholesterol esterase

Correct Answer: HMG-CoA reductase

Q4. Which lipoprotein is primarily responsible for reverse cholesterol transport to the liver?

  • Chylomicrons
  • VLDL
  • LDL
  • HDL

Correct Answer: HDL

Q5. Which bile component emulsifies dietary lipids during digestion?

  • Bile pigments
  • Bile salts
  • Cholesterol
  • Phosphatidylcholine

Correct Answer: Bile salts

Q6. Pancreatic lipase primarily hydrolyzes which bond in triacylglycerols?

  • Phosphoester bond
  • Glycerol–fatty acid ester bond
  • Peptide bond
  • Glycosidic bond

Correct Answer: Glycerol–fatty acid ester bond

Q7. Which apolipoprotein is the main ligand for the LDL receptor?

  • ApoA-I
  • ApoB-100
  • ApoC-II
  • ApoE

Correct Answer: ApoB-100

Q8. Which process generates ketone bodies from fatty acids?

  • Glycolysis
  • Beta-oxidation followed by hepatic ketogenesis
  • Fatty acid synthesis in adipose tissue
  • Cholesterol esterification

Correct Answer: Beta-oxidation followed by hepatic ketogenesis

Q9. Essential fatty acids must be obtained from the diet because humans cannot synthesize which double bond?

  • Delta-9
  • Delta-6 and delta-3 (omega-6 and omega-3)
  • Delta-12
  • Delta-4

Correct Answer: Delta-6 and delta-3 (omega-6 and omega-3)

Q10. Which phospholipase releases arachidonic acid from membrane phospholipids?

  • Phospholipase A2
  • Phospholipase C
  • Phospholipase D
  • Lipoxygenase

Correct Answer: Phospholipase A2

Q11. Which eicosanoid pathway produces prostaglandins and thromboxanes?

  • 5-lipoxygenase pathway
  • Cyclooxygenase (COX) pathway
  • Cytochrome P450 epoxygenase
  • Peroxisomal oxidation

Correct Answer: Cyclooxygenase (COX) pathway

Q12. Which lipid class contains a sphingosine backbone?

  • Glycerophospholipids
  • Sphingolipids
  • Triacylglycerols
  • Free sterols

Correct Answer: Sphingolipids

Q13. Which molecule increases membrane order and decreases fluidity at physiological temperatures?

  • Unsaturated phospholipids
  • Cholesterol
  • Sphingomyelin only
  • Free fatty acids

Correct Answer: Cholesterol

Q14. The major storage form of lipids in adipose tissue is:

  • Phospholipids
  • Cholesterol esters
  • Triacylglycerols
  • Steroid hormones

Correct Answer: Triacylglycerols

Q15. Which transport protein catalyzes esterification of cholesterol in HDL?

  • ACAT (acyl-CoA:cholesterol acyltransferase)
  • LCAT (lecithin–cholesterol acyltransferase)
  • HMG-CoA synthase
  • CETP (cholesteryl ester transfer protein)

Correct Answer: LCAT (lecithin–cholesterol acyltransferase)

Q16. Which lipoprotein carries dietary triglycerides from intestine to peripheral tissues?

  • HDL
  • Chylomicrons
  • LDL
  • IDL

Correct Answer: Chylomicrons

Q17. Which vitamin is lipid-soluble and derived from diet and involved in vision?

  • Vitamin C
  • Vitamin A
  • Vitamin B12
  • Vitamin B6

Correct Answer: Vitamin A

Q18. Statins lower plasma cholesterol by inhibiting which enzyme?

  • HMG-CoA reductase
  • Acyl-CoA oxidase
  • Fatty acid synthase
  • Pancreatic lipase

Correct Answer: HMG-CoA reductase

Q19. Which fatty acid oxidation occurs in peroxisomes rather than mitochondria for very long-chain fatty acids?

  • Beta-oxidation
  • Alpha-oxidation and initial shortening
  • Omega-oxidation exclusively
  • Fatty acid synthesis

Correct Answer: Alpha-oxidation and initial shortening

Q20. Which lipid-derived molecule acts as a second messenger produced by phospholipase C?

  • Ceramide
  • Diacylglycerol (DAG) and IP3
  • Lecithin
  • Prostaglandin E2

Correct Answer: Diacylglycerol (DAG) and IP3

Q21. Which enzyme transfers fatty acyl groups during triglyceride synthesis in the liver?

  • Acyl-CoA synthetase
  • Acyltransferases (e.g., DGAT)
  • Hormone-sensitive lipase
  • Pancreatic lipase

Correct Answer: Acyltransferases (e.g., DGAT)

Q22. Deficiency of essential fatty acids typically leads to which clinical sign?

  • Rickets
  • Dermatitis and impaired wound healing
  • Scurvy
  • Night blindness

Correct Answer: Dermatitis and impaired wound healing

Q23. Which enzyme activates fatty acids to acyl-CoA derivatives?

  • Acetyl-CoA carboxylase
  • Acyl-CoA synthetase (thiokinase)
  • Fatty acid synthase
  • HMG-CoA reductase

Correct Answer: Acyl-CoA synthetase (thiokinase)

Q24. Which lipid is a precursor for steroid hormones?

  • Sphingomyelin
  • Cholesterol
  • Phosphatidylserine
  • Triglycerides

Correct Answer: Cholesterol

Q25. Which molecule transports dietary lipids across the enterocyte to form chylomicrons?

  • Micelles formed with bile salts
  • Lipoprotein lipase
  • Albumin
  • Vitamin D binding protein

Correct Answer: Micelles formed with bile salts

Q26. Sphingomyelin is abundant in which tissue due to its role in insulation?

  • Liver parenchyma
  • Adipose tissue
  • Myelin sheath of nerve cells
  • Skeletal muscle

Correct Answer: Myelin sheath of nerve cells

Q27. Elevated LDL cholesterol is most closely associated with increased risk of:

  • Osteoporosis
  • Atherosclerosis and coronary artery disease
  • Hemophilia
  • Type I diabetes

Correct Answer: Atherosclerosis and coronary artery disease

Q28. Which enzyme in adipose tissue is activated by hormone-sensitive lipase during fasting?

  • Diacylglycerol acyltransferase
  • Hormone-sensitive lipase (itself regulated)
  • Acyl-CoA:cholesterol acyltransferase
  • Pancreatic lipase

Correct Answer: Hormone-sensitive lipase (itself regulated)

Q29. Lipid rafts in the plasma membrane are enriched in which components?

  • Unsaturated phospholipids and low cholesterol
  • Sphingolipids and cholesterol
  • Triglycerides and glycolipids
  • Free fatty acids only

Correct Answer: Sphingolipids and cholesterol

Q30. Which test measures long-term glycemic control and is unrelated to lipid profile?

  • Serum triglycerides
  • Hemoglobin A1c (HbA1c)
  • Total cholesterol
  • LDL cholesterol

Correct Answer: Hemoglobin A1c (HbA1c)

Q31. Which apolipoprotein activates lipoprotein lipase?

  • ApoA-I
  • ApoC-II
  • ApoB-48
  • ApoE

Correct Answer: ApoC-II

Q32. Which fatty acid synthesis enzyme complex is primarily cytosolic and uses NADPH?

  • Beta-oxidation enzymes
  • Fatty acid synthase complex
  • Acyl-CoA oxidase
  • HMG-CoA lyase

Correct Answer: Fatty acid synthase complex

Q33. Which condition results from defects in peroxisomal beta-oxidation affecting very long-chain fatty acids?

  • Hartnup disease
  • Refsum disease or Zellweger spectrum disorders
  • Phenylketonuria
  • Maple syrup urine disease

Correct Answer: Refsum disease or Zellweger spectrum disorders

Q34. Which lipid mediator is mainly involved in bronchoconstriction in asthma?

  • Prostacyclin (PGI2)
  • Leukotriene C4/D4/E4
  • Thromboxane A2
  • Cholesterol

Correct Answer: Leukotriene C4/D4/E4

Q35. Which enzyme hydrolyzes cholesteryl esters in lipoproteins?

  • Hormone-sensitive lipase
  • Cholesterol ester hydrolase (hepatic CE hydrolase)
  • Phospholipase A2
  • Acyl-CoA dehydrogenase

Correct Answer: Cholesterol ester hydrolase (hepatic CE hydrolase)

Q36. Which transporter on enterocytes facilitates uptake of cholesterol from micelles?

  • NPC1L1 (Niemann-Pick C1-Like 1)
  • ABCA1
  • SR-BI
  • CD36

Correct Answer: NPC1L1 (Niemann-Pick C1-Like 1)

Q37. Omega-3 fatty acids are known to have which beneficial cardiovascular effect?

  • Increase LDL oxidation
  • Reduce triglyceride levels and have anti-inflammatory effects
  • Promote platelet aggregation
  • Increase blood pressure

Correct Answer: Reduce triglyceride levels and have anti-inflammatory effects

Q38. Which enzyme converts phosphatidylinositol 4,5-bisphosphate to DAG and IP3?

  • Phospholipase A2
  • Phospholipase C
  • Phospholipase D
  • Phosphatidylinositol kinase

Correct Answer: Phospholipase C

Q39. Which lipid class contains carbohydrate residues and is important in cell recognition?

  • Glycerophospholipids
  • Glycosphingolipids (e.g., gangliosides)
  • Triglycerides
  • Free cholesterol

Correct Answer: Glycosphingolipids (e.g., gangliosides)

Q40. Which enzyme catalyzes the first committed step in fatty acid synthesis?

  • Acetyl-CoA carboxylase (ACC)
  • HMG-CoA reductase
  • Carnitine palmitoyltransferase I
  • Fatty acyl-CoA oxidase

Correct Answer: Acetyl-CoA carboxylase (ACC)

Q41. Carnitine palmitoyltransferase I (CPT I) is inhibited by which molecule to regulate fatty acid oxidation?

  • Malonyl-CoA
  • Acetyl-CoA
  • Coenzyme A
  • Free carnitine

Correct Answer: Malonyl-CoA

Q42. Which lipid-lowering drug enhances removal of LDL by upregulating LDL receptors?

  • Statins (HMG-CoA reductase inhibitors)
  • Bile acid sequestrants only
  • Niacin solely
  • Fibrates only

Correct Answer: Statins (HMG-CoA reductase inhibitors)

Q43. Which serum test is most specific for assessing risk related to atherogenic lipoproteins?

  • Triglyceride/HDL ratio
  • LDL cholesterol concentration
  • Serum albumin
  • Serum creatinine

Correct Answer: LDL cholesterol concentration

Q44. Lipoprotein lipase deficiency leads to accumulation of which particle type?

  • HDL particles
  • Chylomicrons
  • LDL particles
  • VLDL remnants

Correct Answer: Chylomicrons

Q45. Which lipid-derived molecule acts as a vasodilator and inhibitor of platelet aggregation?

  • Thromboxane A2
  • Prostaglandin I2 (prostacyclin)
  • Leukotriene B4
  • Platelet-activating factor

Correct Answer: Prostaglandin I2 (prostacyclin)

Q46. Which transporter mediates cholesterol efflux from macrophages to HDL?

  • NPC1L1
  • ABCA1
  • CETP
  • SR-BI only

Correct Answer: ABCA1

Q47. Which epidermal lipid is crucial for skin barrier function and water retention?

  • Cholesteryl esters only
  • Ceramides
  • Triacylglycerols exclusively
  • Sphingomyelin only

Correct Answer: Ceramides

Q48. Which enzyme is essential for formation of mixed micelles in the intestine by phospholipid remodeling?

  • Lecithin–cholesterol acyltransferase
  • Phospholipase A2 and bile salts aiding micelle formation
  • HMG-CoA reductase
  • Fatty acid synthase

Correct Answer: Phospholipase A2 and bile salts aiding micelle formation

Q49. Which lipid abnormality is typically targeted by fibrates?

  • Elevated LDL cholesterol
  • Hypertriglyceridemia (elevated VLDL/triglycerides)
  • Low HDL due to genetic ApoA-I mutation
  • Reduced bile acid synthesis

Correct Answer: Hypertriglyceridemia (elevated VLDL/triglycerides)

Q50. Glycosylphosphatidylinositol (GPI) anchors are used to:

  • Store triglycerides in adipocytes
  • Anchor certain proteins to the cell membrane
  • Transport fatty acids into mitochondria
  • Synthesize cholesterol in the ER

Correct Answer: Anchor certain proteins to the cell membrane

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