Free Bioenergetics MCQs with Answers

• A. Glyoxysomes
• B. Mitochondria
• C. Peroxisomes
• D. Ribosomes

Explanation: Glycine generated during photorespiration is converted to serine, in the mitochondria which liberates CO2 and ammonia and leads to the…

• A. 1
• B. 2
• C. 3
• D. 4

Explanation: Without oxygen, organisms must use anaerobic respiration to produce ATP, and this process produces only two molecules of ATP per molecule…

• A. Protists
• B. Algae
• C. Fungi
• D. Bacteria

Explanation: In 1931, Van Neil studied the process of photosynthesis in bacteria, particularly sulfur bacteria and green sulfur bacteria.

• A. Mitochondria
• B. Thylakoid membrane of the chloroplast
• C. Stroma of the chloroplast
• D. Cytoplasm of the cell

Explanation: The light-dependent reactions of photosynthesis take place within the thylakoids.

• A. Hydrogen sulphide
• B. Carbon dioxide
• C. Water
• D. Hydrogen peroxide

Explanation: In photosynthesis, photosystem II loses its electrons when excited by photons.

• A. Oxygen
• B. Carbon
• C. Hyrogen
• D. None of these

Explanation: Oxidative phosphorylation involves the release of energy in the form of ATP when reduced coenzymes (NADH, FADH2) pass through a series of…

• A. 2
• B. 3
• C. 4
• D. 1

Explanation: In oxidative phosphorylation, the oxidation or loss of electrons by NADH yields three ATP molecules.

• A. Calvin Cycle
• B. Glycolysis
• C. Kreb's Cycle
• D. None of these

Explanation: Hexokinase is an enzyme used in the phosphorylation of glucose during the first step of glycolysis.

• A. Aerobic respiration
• B. Photosynthesis
• C. None of these
• D. Anaerobic respiration

Explanation: C6H12O6 + 6O2 → 6CO2 + 6H2O + energy is the equation of aerobic respiration.

• A. 3
• B. 2
• C. 1
• D. 4

Explanation: In glycolysis, the conversion of glycerate-1,3-bisphosphate to glycerate-3-phosphate involves the loss of one phosphate molecule.

• A. ATP
• B. NADP
• C. NAD
• D. FAD

Explanation: NAD (nicotinamide adenine dinucleotide) is involved in the oxidation of malate to oxaloacetate in the Krebs's Cycle.

• A. Cytochrome a
• B. Cytochrome a3
• C. Coenzyme C
• D. Coenzyme Q

Explanation: This option is the correct answer. Coenzyme Q (also known as ubiquinone) is involved in the electron transport chain, but it acts as a…

• A. Matrix of mitochondria
• B. Outer membrane of mitochondria
• C. Inner membrane of mitochondria
• D. Cytoplasmic matrix In cystic fibrosis

Explanation: The carriers of the respiratory chain are located on the inner membrane of mitochondria.

• A. ATP
• B. NADP
• C. NADP and ATP
• D. NADP, ATP, and O2

Explanation: The primary product of cyclic photophosphorylation in photosynthesis is ATP (adenosine triphosphate).

• A. 6
• B. 3
• C. 8
• D. 4

Explanation: The total NADH formed by one glucose molecule during the Krebs cycle is 6.

• A. Hydrogen
• B. Iron
• C. Cytochrome
• D. Oxygen

Explanation: The terminal electron acceptor in the electron transport chain is oxygen (O2).

• A. Fumarate to Malate
• B. Succinate to Fumarate
• C. Malate to Oxaloacetate
• D. α-Ketoglutarate to Succinate

Explanation: The conversion of succinate to fumarate is the correct step where one molecule of FADH₂ is produced in the Krebs cycle.

• A. Ribose and heptolose
• B. Glyceraldehyde and dihydroxyacetone
• C. Glucose and galactose
• D. Fructose and ribulose

Explanation: Glyceraldehyde and dihydroxyacetone are intermediates in both glycolysis (respiration) and the Calvin cycle (photosynthesis).

• A. Mitochondrial inner membrane
• B. Cytoplasm
• C. Outer membrane of mitochondria
• D. Stroma of the chloroplast

Explanation: Oxidative phosphorylation, which is the process of synthesizing ATP using oxygen, takes place on the inner membrane of mitochondria.

• A. Glycerate
• B. Lactic Acid
• C. Pyruvate
• D. Succinic Acid

Explanation: Glycolysis is the breakdown of glucose into two molecules of pyruvate. During glycolysis, which takes place in the cytoplasm of the cell…