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: Enzymes accelerate reactions by lowering
A) Product concentration
B) Substrate level
C) Reaction volume
D) Activation energy
✅ Correct Answer: D
Explanation: Enzymes reduce the activation energy needed for reactions.
Q: Glycolysis takes place in the
A) Mitochondria
B) Cytoplasm
C) Ribosome
D) Nucleus
✅ Correct Answer: B
Explanation: Glycolysis is a cytoplasmic process that breaks down glucose.
Q: Cholesterol is classified as a
A) Protein
B) Lipid
C) Carbohydrate
D) Nucleic acid
✅ Correct Answer: B
Explanation: Cholesterol is a type of lipid involved in membrane structure.
Q: DNA is made up of
A) Fatty acids
B) Amino acids
C) Nucleotides
D) Sugars
✅ Correct Answer: C
Explanation: Nucleotides are the building blocks of DNA.
Q: Enzymes act as
A) Structural units
B) Transport proteins
C) Biological catalysts
D) Immune markers
✅ Correct Answer: C
Explanation: Enzymes speed up biochemical reactions without being consumed.
Q: Triglycerides are composed of
A) Fatty acids and glycerol
B) Proteins and lipids
C) Glycerol and glucose
D) Fatty acids and nucleotides
✅ Correct Answer: A
Explanation: Triglycerides are formed from glycerol and three fatty acids.
Q: RNA contains the sugar
A) Ribose
B) Glucose
C) Fructose
D) Deoxyribose
✅ Correct Answer: A
Explanation: Ribose is the sugar present in RNA molecules.
Q: Peptide bonds are found in
A) Nucleic acids
B) Proteins
C) Lipids
D) Carbohydrates
✅ Correct Answer: B
Explanation: Peptide bonds link amino acids to form proteins.
Q: The central dogma of molecular biology is
A) DNA → Protein → RNA
B) RNA → DNA → Protein
C) DNA → RNA → Protein
D) Protein → DNA → RNA
✅ Correct Answer: C
Explanation: Genetic information flows from DNA to RNA to protein.
Q: Urea cycle occurs mainly in the
A) Liver
B) Kidney
C) Pancreas
D) Brain
✅ Correct Answer: A
Explanation: The liver converts toxic ammonia into urea in the urea cycle.