Sample objective questions on the above topics

Here are some sample objective questions on cofactors, coenzymes, and vitamins:

1. Which of the following is a water-soluble vitamin that acts as a coenzyme in numerous redox reactions and is crucial for energy metabolism? a) Vitamin A b) Vitamin D c) Vitamin C d) Vitamin K

2. A metal ion that is tightly bound to an enzyme and is essential for its catalytic activity is called a: a) Coenzyme b) Apoenzyme c) Holoenzyme d) Prosthetic group

3. Which vitamin is a precursor to NAD⁺ and NADP⁺, which are vital coenzymes in many metabolic pathways, including glycolysis and the pentose phosphate pathway? a) Riboflavin (Vitamin B₂) b) Niacin (Vitamin B₃) c) Pyridoxine (Vitamin B₆) d) Cobalamin (Vitamin B₁₂)

4. Heme, found in hemoglobin and cytochromes, contains which metal ion cofactor? a) Zinc (Zn²⁺) b) Magnesium (Mg²⁺) c) Iron (Fe²⁺/Fe³⁺) d) Copper (Cu²⁺)

5. A deficiency in Vitamin B₁₂ can lead to pernicious anemia because this vitamin is essential for: a) Collagen synthesis b) Red blood cell formation and DNA synthesis c) Vision and immune function d) Blood clotting