CN Nutritional Science & Biochemistry 3 — Questions and Answers
Question 1: Which mineral is a central component of the heme group in hemoglobin?
- Iron (Correct answer)
- Zinc
- Copper
- Magnesium
Correct answer: Iron
Iron binds oxygen within the heme prosthetic group of hemoglobin.
Question 2: Vitamin C is required as a cofactor for the hydroxylation of which structural protein?
- Collagen (Correct answer)
- Keratin
- Elastin
- Albumin
Correct answer: Collagen
Vitamin C is a cofactor for prolyl and lysyl hydroxylases in collagen synthesis.
Question 3: Which of the following is a ketone body produced during prolonged fasting?
- Beta-hydroxybutyrate (Correct answer)
- Pyruvate
- Lactate
- Oxaloacetate
Correct answer: Beta-hydroxybutyrate
Beta-hydroxybutyrate is a major ketone body used as fuel during fasting.
Question 4: The Krebs (citric acid) cycle takes place in which cellular compartment?
- Mitochondrial matrix (Correct answer)
- Cytoplasm
- Nucleus
- Endoplasmic reticulum
Correct answer: Mitochondrial matrix
The citric acid cycle enzymes are located in the mitochondrial matrix.
Question 5: Which fat-soluble vitamin is synthesized in the skin upon UV exposure?
- Vitamin D (Correct answer)
- Vitamin A
- Vitamin E
- Vitamin K
Correct answer: Vitamin D
Vitamin D is produced from 7-dehydrocholesterol when skin is exposed to UVB light.
Question 6: Which hormone lowers blood glucose by promoting cellular glucose uptake?
- Insulin (Correct answer)
- Glucagon
- Cortisol
- Epinephrine
Correct answer: Insulin
Insulin, released by pancreatic beta cells, drives glucose into cells.
Question 7: Essential fatty acids in the human diet include linoleic acid and which other?
- Alpha-linolenic acid (Correct answer)
- Oleic acid
- Palmitic acid
- Stearic acid
Correct answer: Alpha-linolenic acid
Alpha-linolenic acid (omega-3) and linoleic acid (omega-6) cannot be synthesized by humans.
CN Nutritional Science & Biochemistry 3
Which mineral is a central component of the heme group in hemoglobin?