Free Bioenergetics MCQs with Answers

• A. CO2 Fixation
• B. Phosphorylation
• C. Reduction
• D. Regeneration

Explanation: The process of recreating a molecule that is used in a cyclic pathway, like the regeneration of ribulose-1,5-bisphosphate (RuBP) in the…

• A. Faster in anaerobic respiration
• B. Faster in aerobic respiration
• C. The same in both types of respiration
• D. Not associated with respiration

Explanation: Anaerobic respiration is generally faster than aerobic respiration because it does not require oxygen, allowing cells to produce energy…

• A. Lactic acid fermentation
• B. Alcoholic fermentation
• C. Cellular respiration
• D. None of the above

Explanation: Alcoholic fermentation is an anaerobic process used by yeast and some bacteria to produce energy.

• A. Fermentation
• B. Glycolysis
• C. Oxidative phosphorylation
• D. Oxidation of pyruvate to acetyl CoA

Explanation: Oxidative phosphorylation is the final stage of cellular respiration, where most of the cell's ATP is produced.

• A. Reduction process
• B. Oxidation process
• C. Redox process
• D. None of the given options

Explanation: Photosynthesis consists of oxidation (water losing electrons) and reduction (carbon dioxide gaining electrons).

• A. Glucose and water
• B. Oxygen and glucose
• C. Oxygen, glucose, and water
• D. None of the given options

Explanation: Photosynthesis produces glucose and oxygen through a chemical processwhere palnts use sunlight,water,carbon dioxide.

• A. 2 ATP are produced and 2 ATP are consumed
• B. 1 ATP is produced and 2 ATP are consumed
• C. 2 ATP are produced and 1 ATP is consumed
• D. 4 ATP are produced and 2 ATP are consumed

Explanation: 4 ATP are produced and 2 ATP are consumed - Correct. Glycolysis generates 4 ATP molecules but consumes 2, leading to a net gain of 2 ATP.

• A. 2H, 2e and 1/2 O₂
• B. 4H, 4e and 2 O₂
• C. 2H, 2e and 2 O₂
• D. 4H, 2e and 4 O₂

Explanation: 2H, 2e and 1/2 O₂ - Correct. Photolysis of water during photosynthesis produces 2 protons (H⁺), 2 electrons (e⁻), and ½ molecule of oxygen…

• A. The molecule that has no role in muscle contraction
• B. The molecule that releases energy when a phosphate molecule is added
• C. The molecule that is only present inside the nucleus
• D. The molecule that releases energy when the phosphate molecule is removed

Explanation: The molecule that releases energy when the phosphate molecule is removed - Correct.

• A. NADH
• B. None of these
• C. Oxygen
• D. Cytochrome complex

Explanation: Oxygen - Correct. Oxygen acts as the final electron acceptor in the electron transport chain, forming water.

• A. Low level of NADPH
• B. High level of NADPH
• C. Low light intensity
• D. High light intensity

Explanation: Cyclic phosphorylation is a process that occurs in the light-dependent reactions of photosynthesis, where electrons are recycled within…

• A. 3-phosphoglyceraldehyde
• B. 3-phosphoglyceric acid
• C. 1,3-biphosphate glycerate
• D. Dihydroxyacetone phosphate

Explanation: 3-phosphoglyceric acid - Correct. This is the first stable 3-carbon compound formed in the Calvin cycle.

• A. PEA > Cytochrome complex > Plastocyanin
• B. PEA > Ferredoxin > Plastocyanin
• C. PEA > Cytochrome complex > Ferredoxin
• D. PEA > Ferredoxin > Cytochrome complex > Plastocyanin

Explanation: PEA > Ferredoxin > Cytochrome complex > Plastocyanin - Correct. In cyclic photophosphorylation, electrons flow from the primary electron…

• A. Regenerate RuBP
• B. Fix CO₂
• C. Convert PGAL to RuP
• D. Convert PGA to PGAL

Explanation: Convert PGA to PGAL - Correct. ATP and NADPH are used in the Calvin cycle to reduce 3-phosphoglycerate (PGA) to glyceraldehyde-3-phosphate…

• A. Auxins
• B. Ribulose bisphosphate
• C. Lactoferrin
• D. Agrobacterium

Explanation: Carbon dioxide fixation, particularly in the context of photosynthesis, can be enhanced by enhancing the efficiency of the enzyme…

• A. Ethanol and Carbon dioxide
• B. Lactate
• C. Pyruvate
• D. Both A and B

Explanation: The end product of glycolysis is always pyruvate

• A. Carbon
• B. Hydrogen
• C. Nitrogen
• D. None of these options is correct.

Explanation: Proteins, carbohydrates, and fats are made from three basic molecules: "carbon", "hydrogen", and "oxygen".

• A. Food-ATP-creatine phosphate- protein
• B. Food-glycogen- ATP-creatine phosphate
• C. Food-glycogen-creatine phosphate- ATP
• D. Food-protein-creatine phosphate- ATP

Explanation: Muscles convert food to energy by first breaking down glycogen to glucose.

• A. Pyruvate
• B. Hydrogenase
• C. Ribulose bisphosphate
• D. Oxaloacetate

Explanation: The first step involves the fixing of carbon (derived from CO2) into molecules of Ribulose Bisphosphate (RuBP) via the action of the…

• A. Day
• B. Night
• C. Dawn and Dusk
• D. Midnight

Explanation: At dawn and dusk, the intensity of light is low. At this moment the amount of oxygen released from photosynthesis is equal to the amount…