MCQ on Lipids and Fats

🟢 Easy Level (1–20)

1. Which of the following is a lipid?
   a) Glucose
   b) Cellulose
   c) Triglyceride ✅
   d) Starch
   Explanation: Triglycerides are a common form of lipids.
2. Which fat is solid at room temperature?
   a) Olive oil
   b) Coconut oil
   c) Butter ✅
   d) Canola oil
   Explanation: Butter is a saturated fat and solid at room temperature.
3. Which type of fat is considered “good” fat?
   a) Trans fat
   b) Saturated fat
   c) Unsaturated fat ✅
   d) Hydrogenated fat
   Explanation: Unsaturated fats help improve blood cholesterol levels.
4. Fats are primarily used by the body for:
   a) Protein synthesis
   b) Oxygen transport
   c) Energy storage ✅
   d) Bone growth
   Explanation: Fats store energy efficiently.
5. Which vitamin requires fat for absorption?
   a) Vitamin C
   b) Vitamin B12
   c) Vitamin D ✅
   d) Vitamin B1
   Explanation: Vitamin D is fat-soluble.
6. Which of the following is a saturated fat?
   a) Sunflower oil
   b) Olive oil
   c) Butter ✅
   d) Fish oil
   Explanation: Saturated fats come from animal sources.
7. Lipids are made of:
   a) Amino acids
   b) Fatty acids and glycerol ✅
   c) Glucose
   d) Nucleotides
   Explanation: Lipids are composed of fatty acids and glycerol backbone.
8. Which fat should be avoided for heart health?
   a) Polyunsaturated fat
   b) Monounsaturated fat
   c) Trans fat ✅
   d) Omega-3 fat
   Explanation: Trans fats raise LDL and lower HDL.
9. Which is a source of omega-3 fatty acids?
   a) Red meat
   b) Cheese
   c) Salmon ✅
   d) Butter
   Explanation: Fatty fish like salmon are rich in omega-3s.
10. Which organ produces bile to help digest fats?
    a) Kidney
    b) Pancreas
    c) Liver ✅
    d) Stomach
    Explanation: Liver produces bile stored in the gallbladder.
11. Which type of fatty acid has no double bonds?
    a) Saturated ✅
    b) Unsaturated
    c) Polyunsaturated
    d) Monounsaturated
    Explanation: Saturated fatty acids have only single bonds.
12. What is the function of bile in fat digestion?
    a) Breaks fats into glycerol
    b) Absorbs fat into the blood
    c) Emulsifies fats ✅
    d) Synthesizes cholesterol
    Explanation: Bile breaks fat into smaller droplets.
13. Which fat is found mostly in plant oils?
    a) Saturated fat
    b) Monounsaturated fat ✅
    c) Trans fat
    d) Cholesterol
    Explanation: Olive and canola oils contain monounsaturated fats.
14. Fats contain how many calories per gram?
    a) 4
    b) 7
    c) 9 ✅
    d) 12
    Explanation: Fats provide 9 kcal/gram.
15. Which molecule stores fat in the body?
    a) Glycogen
    b) ATP
    c) Triglyceride ✅
    d) Enzyme
    Explanation: Body fat is mainly stored as triglycerides.
16. Excess intake of fats may cause:
    a) Anemia
    b) Obesity ✅
    c) Rickets
    d) Scurvy
    Explanation: High-fat diets can lead to weight gain.
17. What part of the cell membrane is made from lipids?
    a) Ribosome
    b) Phospholipid bilayer ✅
    c) Nucleus
    d) DNA
    Explanation: Cell membranes are composed of lipid layers.
18. HDL stands for:
    a) High Digestion Lipid
    b) High Density Lipoprotein ✅
    c) Heavy Dietary Lipid
    d) Hydrogenated Dietary Lipid
    Explanation: HDL is the “good” cholesterol.
19. Cholesterol is a type of:
    a) Protein
    b) Carbohydrate
    c) Lipid ✅
    d) Vitamin
    Explanation: Cholesterol is a lipid essential for cell membranes.
20. Which fat is formed artificially by hydrogenation?
    a) Saturated fat
    b) Trans fat ✅
    c) Unsaturated fat
    d) Omega-6 fat
    Explanation: Trans fats are made during hydrogenation of oils.

🟡 Moderate Level (21–40)

21. Which enzyme breaks down fats in digestion?
    a) Amylase
    b) Lipase ✅
    c) Pepsin
    d) Maltase
    Explanation: Lipase breaks triglycerides into fatty acids.
22. Which of the following is a phospholipid?
    a) Cholesterol
    b) Lecithin ✅
    c) Glucose
    d) Maltose
    Explanation: Lecithin is a major component of cell membranes.
23. Fatty acids with one double bond are called:
    a) Saturated
    b) Polyunsaturated
    c) Monounsaturated ✅
    d) Trans
    Explanation: Mono = one double bond.
24. Which of these is an essential fatty acid?
    a) Oleic acid
    b) Stearic acid
    c) Linoleic acid ✅
    d) Palmitic acid
    Explanation: Linoleic acid (omega-6) is essential.
25. Which lipoprotein is considered “bad” cholesterol?
    a) HDL
    b) LDL ✅
    c) VLDL
    d) Chylomicron
    Explanation: LDL contributes to arterial plaque.
26. A diet rich in saturated fats increases the risk of:
    a) Vitamin deficiency
    b) High blood pressure
    c) Heart disease ✅
    d) Liver cirrhosis
    Explanation: Saturated fat increases cholesterol levels.
27. What is hydrogenation?
    a) Removing fat from food
    b) Breaking down fat
    c) Adding hydrogen to unsaturated fats ✅
    d) Absorbing fat in cells
    Explanation: Hydrogenation turns liquid fats solid.
28. Which is NOT a characteristic of unsaturated fats?
    a) Liquid at room temperature
    b) Plant source
    c) No double bonds ✅
    d) Lower LDL levels
    Explanation: Unsaturated fats do have double bonds.
29. Fat is primarily stored in:
    a) Muscles
    b) Skin
    c) Adipose tissue ✅
    d) Liver
    Explanation: Adipose tissue stores fat under skin and around organs.
30. Which compound carries lipids through the bloodstream?
    a) Hemoglobin
    b) Insulin
    c) Lipoprotein ✅
    d) Enzyme
    Explanation: Lipoproteins transport cholesterol and fat.
31. Which food is highest in saturated fats?
    a) Avocado
    b) Olive oil
    c) Cheese ✅
    d) Almonds
    Explanation: Animal products like cheese contain saturated fats.
32. Which of the following is a function of lipids?
    a) Forming enzymes
    b) Providing energy ✅
    c) Building DNA
    d) Transporting oxygen
    Explanation: Lipids are a dense energy source.
33. Which of the following increases HDL levels?
    a) Trans fat
    b) Physical activity ✅
    c) Smoking
    d) Sugar intake
    Explanation: Exercise can improve HDL (“good” cholesterol).
34. Excessive cholesterol deposits in arteries cause:
    a) Diabetes
    b) Atherosclerosis ✅
    c) Anemia
    d) Osteoporosis
    Explanation: Cholesterol build-up narrows arteries.
35. Lipids differ from carbohydrates because they:
    a) Have nitrogen
    b) Are water-soluble
    c) Yield more energy per gram ✅
    d) Are composed of amino acids
    Explanation: Lipids provide 9 kcal/g vs 4 kcal/g for carbs.
36. Lipoproteins are made of:
    a) Sugars and proteins
    b) Fats and proteins ✅
    c) Starch and protein
    d) Glycerol and water
    Explanation: They have lipid and protein components.
37. Which condition results from low fat intake?
    a) Vitamin toxicity
    b) Scurvy
    c) Fat-soluble vitamin deficiency ✅
    d) High cholesterol
    Explanation: Vitamins A, D, E, K require fats.
38. Omega-3 fatty acids help prevent:
    a) Obesity
    b) Atherosclerosis ✅
    c) Kidney stones
    d) Arthritis
    Explanation: Omega-3s reduce inflammation and cholesterol.
39. Which is a polyunsaturated fat?
    a) Palm oil
    b) Olive oil
    c) Corn oil ✅
    d) Butter
    Explanation: Corn oil contains multiple double bonds.
40. Which structure in lipids makes them hydrophobic?
    a) Glycerol head
    b) Fatty acid tail ✅
    c) Double bond
    d) Phosphate group
    Explanation: Long hydrocarbon chains repel water.

🔴 Hard Level (41–50)

41. Eicosanoids are derived from:
    a) Cholesterol
    b) Amino acids
    c) Fatty acids ✅
    d) Glucose
    Explanation: They’re made from arachidonic acid (a fatty acid).
42. Which lipoprotein transports cholesterol to the liver for excretion?
    a) LDL
    b) HDL ✅
    c) VLDL
    d) Chylomicron
    Explanation: HDL removes cholesterol from blood.
43. A triglyceride has how many fatty acid chains?
    a) 1
    b) 2
    c) 3 ✅
    d) 4
    Explanation: “Tri” means three fatty acid tails.
44. Fat emulsification increases:
    a) Enzyme inhibition
    b) Fat oxidation
    c) Surface area ✅
    d) Blood cholesterol
    Explanation: Emulsification makes fats more accessible to enzymes.
45. Essential fatty acids cannot be:
    a) Stored in adipose
    b) Found in plants
    c) Synthesized by the body ✅
    d) Used for energy
    Explanation: Must be obtained from diet.
46. Fatty acid oxidation occurs in the:
    a) Nucleus
    b) Mitochondria ✅
    c) Cytoplasm
    d) Ribosome
    Explanation: Beta-oxidation happens in mitochondria.
47. Which statement about trans fats is TRUE?
    a) They raise HDL
    b) They improve heart health
    c) They occur naturally in all oils
    d) They increase LDL ✅
    Explanation: Trans fats increase bad cholesterol.
48. Lipids in membranes are mostly:
    a) Triglycerides
    b) Phospholipids ✅
    c) Steroids
    d) Trans fats
    Explanation: Membranes are made of phospholipid bilayers.
49. The main sterol in animal tissue is:
    a) Testosterone
    b) Cholesterol ✅
    c) Estrogen
    d) Glycerol
    Explanation: Cholesterol is the base sterol in animals.
50. Lipolysis is the process of:
    a) Lipid storage
    b) Breaking down fat ✅
    c) Fat synthesis
    d) Cholesterol absorption
    Explanation: Lipolysis releases fatty acids from stored fat.