Free Bioenergetics MCQs with Answers
1,378 Bioenergetics MCQs from Biology, each with the correct answer and a written explanation of why it is correct. Free and unlimited, with no account needed.
Cellular respiration explains how cells release energy from glucose through glycolysis, the link reaction, Krebs cycle and electron transport chain. It includes ATP production, substrate-level and oxidative phosphorylation, aerobic versus anaerobic respiration, and the roles of mitochondria, oxygen and fermentation in energy transfer.
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Read the Bioenergetics notesFree MDCAT chapter notes with key terms1,378 questions · page 28 of 69
- A. Carbon
- B. Hydrogen
- C. Magnesium
- D. Nitrogen
Explanation: Magnesium has two electrons in its outer shell, so it has a tendency to lose them.
Correct answer: Magnesium- A. Blue light is given to the plant
- B. Red light is given to the plant
- C. Green light is given to the plant
- D. Yellow light is given to the plant
Explanation: Red light is more effective in photosynthesis because both the photosystems absorb light of wavelengths between 680 and 700 nm…
Correct answer: Red light is given to the plant- A. Six
- B. Fifty five
- C. Seventy
- D. Seventy two
Explanation: Molecular formula of Chlorophyll-a is C₅₅H₇₂O₅N₄Mg.Hence, option D is correct because the number of hydrogen atoms in the molecular…
Correct answer: Seventy two- A. Active
- B. At high energy level
- C. At low energy level
- D. Gets chemically deativated after electronic transfer
Explanation: Oxygen has high affinity for electrons which make it ideal to accept electrons so it is at low energy level so that it will accept more…
Correct answer: At low energy level- A. Oxygen
- B. Chlorophyll
- C. ATP
- D. Light
Explanation: Oxygen is a chemical element (symbol O) essential for life on Earth. It is a colorless, odorless gas that makes up about 21% of the…
Correct answer: Oxygen- A. Photorespiration
- B. Oxidative phosphorylation
- C. Non-cyclic photophosphorylation
- D. Cyclic oxidative phosphorylation
Explanation: The process you're describing is called photorespiration. During photorespiration, plants take up oxygen and release carbon dioxide, which…
Correct answer: Photorespiration- A. Oxidative phosphorylation
- B. Cyclic photophosphorylation-
- C. Non-cyclic oxidative phosphorylation
- D. Non-cyclic photephosphorylation
Explanation: Non-cyclic photophosphorylation is often illustrated using the Z-scheme model.
Correct answer: Non-cyclic photephosphorylation- A. Carotenoids
- B. Fucoxanthin
- C. Xanthophyll
- D. Chlorophyll
Explanation: Carotenoids are found in both plants and human.In plants,carotenoids play a role in photosynthesis by absorbing light, while inhumans…
Correct answer: Carotenoids- A. 3-PGA
- B. G3P
- C. 6-Carbon unstable intermediate
- D. 1,3 bisphosphoglycerate
Explanation: The reaction in the Calvin cycle where CO₂ reacts with RuBP produces a 6-carbon unstable intermediate because of the way carbon fixation…
Correct answer: 6-Carbon unstable intermediate- A. Chemical formula C55H70O6N4Mg
- B. Porphyrin ring with nitrogen in centre
- C. Methyl group on second pyrrole ring
- D. Aldehyde group on second pyrrole ring
Explanation: The statement "Methyl group on the second pyrrole ring" in the context of chlorophyll a is correct.The presence of a methyl group on the…
Correct answer: Methyl group on second pyrrole ring- A. Plastoquinone
- B. Cytochrome complex
- C. P700
- D. Primary electron acceptor of PS1
Explanation: Plastocyanin is reduced when it accepts an electron from the cytochrome b6f complex, and this electron reduces the copper ion in…
Correct answer: Cytochrome complex- A. Reducing NADP+
- B. Oxidizing NADP+
- C. Reducing Ferredoxin
- D. Reducing P700
Explanation: NADP reductase is an enzyme that plays a key role in the light-dependent reactions of photosynthesis.
Correct answer: Reducing NADP+- A. Water
- B. Plastoquinone
- C. Plastocyanin
- D. Ferredoxin
Explanation: Water is the true source of electrons for PS II, where photolysis (splitting of water) provides the electrons to start the chain.
Correct answer: Water- A. 2%
- B. 4%
- C. 10%
- D. 36%
Explanation: Option A is the correct option because This is the accurate estimate for energy conserved as ATP in anaerobic respiration.
Correct answer: 2%- A. Carbon dioxide
- B. NADPH
- C. Oxygen
- D. Water
Explanation: The end product of the electron transport chain (ETC) in the inner mitochondrial membrane is water (H₂O).
Correct answer: Water- A. When 1,3-bisphosphoglycerate is converted into 3-phosphoglycerate
- B. When fructose 6-phospate is converted into fructose 1,6-bisphosphate
- C. When glucose is converted into glucose 6- phosphate
- D. When glyceraldehyde 3-phosphate is converted into 1,3-bisphosphoglycerate
Explanation: ATP is not directly involved in the conversion of glyceraldehyde-3-phosphate to 1,3-bisphosphoglycerate in glycolysis.
Correct answer: When glyceraldehyde 3-phosphate is converted into 1,3-bisphosphoglycerate- A. Absorption of light
- B. ATP synthesis
- C. Photoexcitation
- D. Photolysis of water
Explanation: Photolysis of water occurs only in non-cyclic photophosphorylation, where water is split to release electrons, protons, and oxygen.
Correct answer: Photolysis of water- A. Cyclic Phosphorylation
- B. Non-cyclic Phosphorylation
- C. Oxidative Phosphorylation
- D. Substrate level Phosphorylation
Explanation: ATP generation in the mitochondria's electron transport chain, where electrons move through complexes, ultimately combining with oxygen to…
Correct answer: Oxidative Phosphorylation- A. Coenzyme Q
- B. Cytochrome a
- C. Cytochrome b
- D. Cytochrome c
Explanation: Coenzyme Q, also known as ubiquinone, is a lipid-soluble molecule in the electron transport chain located in the inner mitochondrial…
Correct answer: Coenzyme Q- A. 0.003-0.004%
- B. 0.03-0.04%
- C. 0.3-0.4%
- D. 3-4%
Explanation: The correct answer is Option B:0.03-0.04%. The range of carbon dioxide in the air is typically around 0.03-0.04%.
Correct answer: 0.03-0.04%