IIN Macronutrient & Micronutrient Science 3 — Questions and Answers
Question 1: Which fat-soluble vitamin is produced in the skin upon exposure to ultraviolet B radiation from sunlight?
- Vitamin A
- Vitamin E
- Vitamin K
- Vitamin D (Correct answer)
Correct answer: Vitamin D
UVB radiation converts 7-dehydrocholesterol in the skin to previtamin D3, which is then converted to cholecalciferol (vitamin D3).
Question 2: Glycogen, the storage form of carbohydrate in humans, is primarily stored in which two tissues?
- Kidneys and lungs
- Liver and skeletal muscle (Correct answer)
- Brain and adipose tissue
- Heart and pancreas
Correct answer: Liver and skeletal muscle
The liver stores glycogen to maintain blood glucose levels, while skeletal muscle stores glycogen for local energy use during activity.
Question 3: Which water-soluble B vitamin serves as a coenzyme in energy metabolism and is found in high concentrations in brewer's yeast and whole grains?
- Cobalamin (B12)
- Thiamine (B1) (Correct answer)
- Biotin (B7)
- Folic acid (B9)
Correct answer: Thiamine (B1)
Thiamine (B1) is a coenzyme in pyruvate dehydrogenase and alpha-ketoglutarate dehydrogenase, key enzymes in carbohydrate energy metabolism.
Question 4: Which term describes a protein that contains all nine essential amino acids in adequate proportions?
- Incomplete protein
- Complementary protein
- Complete protein (Correct answer)
- Fibrous protein
Correct answer: Complete protein
A complete protein contains all nine essential amino acids in sufficient quantities to support human protein synthesis.
Question 5: Excess dietary protein that is not needed for tissue synthesis is primarily metabolized by which process?
- Stored as glycogen in the liver
- Converted to fatty acids or glucose after deamination (Correct answer)
- Excreted unchanged in urine
- Converted to vitamins
Correct answer: Converted to fatty acids or glucose after deamination
Amino acids are deaminated, and their carbon skeletons enter metabolic pathways to be converted to glucose (gluconeogenesis) or fatty acids for energy or storage.
Question 6: Which mineral plays a primary role in regulating fluid balance outside of cells (extracellular fluid)?
- Potassium
- Magnesium
- Phosphorus
- Sodium (Correct answer)
Correct answer: Sodium
Sodium is the major extracellular cation, and its concentration gradient across cell membranes drives water movement and fluid balance.
Question 7: A client consuming adequate calories but very low dietary fat may develop deficiency in which group of nutrients?
- Vitamins A, D, E, and K (Correct answer)
- Vitamin C and B vitamins
- Iron and zinc
- Calcium and magnesium
Correct answer: Vitamins A, D, E, and K
Vitamins A, D, E, and K are fat-soluble and require dietary fat for absorption; very low fat intake impairs their uptake.
IIN Macronutrient & Micronutrient Science 3
Which fat-soluble vitamin is produced in the skin upon exposure to ultraviolet B radiation from sunlight?