Biochemistry MCQs
Biochemistry MCQs play a vital role in preparing students for understanding life at the molecular level. These MCQs include topics such as carbohydrate metabolism, lipid and protein structures, enzymes, vitamins, DNA/RNA, and clinical applications. These quizzes are essential for students appearing in MDCAT, USMLE, FCPS, and other competitive exams. Regular practice enhances understanding of how biochemical processes affect human health and disease.
Q: Element found in the structure of heme
A) Magnesium
B) Iron
C) Copper
D) Zinc
✅ Correct Answer: B
Explanation: Iron is the central atom in the heme group and binds oxygen.
Q: Molecule acting as the main electron carrier in respiration
A) ATP
B) Glucose
C) NAD+
D) FADH2
✅ Correct Answer: C
Explanation: NAD+ accepts electrons during metabolic reactions and becomes NADH.
Q: Lipid component contributing to membrane fluidity
A) Triglycerides
B) Cholesterol
C) Phospholipids
D) Glycolipids
✅ Correct Answer: B
Explanation: Cholesterol intercalates between phospholipids, maintaining fluidity and stability.
Q: Level of protein structure formed by alpha helices and beta sheets
A) Secondary
B) Quaternary
C) Tertiary
D) Primary
✅ Correct Answer: A
Explanation: Secondary structure includes alpha helices and beta-pleated sheets.
Q: Function of ribosomal RNA
A) Catalysis of peptide bond formation
B) Gene regulation
C) Lipid synthesis
D) Energy storage
✅ Correct Answer: A
Explanation: rRNA acts as a ribozyme catalyzing peptide bond formation during translation.
Q: Byproduct of anaerobic glycolysis in yeast
A) Citrate
B) Ethanol
C) Acetyl-CoA
D) Lactic acid
✅ Correct Answer: B
Explanation: Yeast converts pyruvate into ethanol under anaerobic conditions.
Q: Protein hormone regulating glucose metabolism
A) Glucagon
B) Thyroxine
C) Insulin
D) Cortisol
✅ Correct Answer: C
Explanation: Insulin lowers blood glucose by promoting its uptake and storage.
Q: Cofactor necessary for collagen synthesis
A) Vitamin C
B) Calcium
C) Iron
D) Zinc
✅ Correct Answer: A
Explanation: Vitamin C is required for hydroxylation of proline and lysine in collagen.
Q: End product of purine degradation
A) Allantoin
B) Uric acid
C) Urea
D) Ammonia
✅ Correct Answer: B
Explanation: Purine bases are ultimately degraded to uric acid.
Q: Type of RNA that brings amino acids during translation
A) tRNA
B) snRNA
C) mRNA
D) rRNA
✅ Correct Answer: A
Explanation: tRNA carries specific amino acids to the ribosome for protein assembly.