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 65 of 69
- A. To cause the breakdown of citric acid
- B. To combine with glucose to produce carbon dioxide
- C. To combine with carbon from organic molecules to produce carbon dioxide
- D. To combine with hydrogen from organic molecules to produce water
Explanation: Function of molecular oxygen in cellular respiration is to combine with hydrogen from organic molecules to produce water.
Correct answer: To combine with hydrogen from organic molecules to produce water- A. ADP from ATP
- B. ATP from ADP
- C. Glucose 6-phosphate from glucose
- D. NADP+ from NAD+
Explanation: During photophosphorylation, light energy is captured by chlorophyll and other pigment molecules in the thylakoid membranes of…
Correct answer: ATP from ADP- A. Alpha ketogluteric acid
- B. Glyceric acid
- C. Citric acid
- D. Acetic acid
Explanation: Acetic acid, also known as ethanoic acid, is a simple organic acid with the chemical formula CH3COOH.
Correct answer: Acetic acid- A. 2 Electrons 1 proton
- B. 2 Electrons 2 protons
- C. Electron 2 protons
- D. 1 Electrons 1 proton
Explanation: Conversion of NAD+ into NADH requires 2 Electrons 1 proton.
Correct answer: 2 Electrons 1 proton- A. Glyceraldehyde-3-phosphate
- B. 3-Phosphoglycerate
- C. Ribulose bisphosphate
- D. 1,3-Bisphosphoglycerate
Explanation: 1,3-Bisphosphoglycerate (1,3-BPG) is a high-energy intermediate in glycolysis, a central metabolic pathway that breaks down glucose to…
Correct answer: 1,3-Bisphosphoglycerate- A. 6 carbon atoms
- B. 3 carbon atoms
- C. 5 carbon atoms
- D. 4 carbon atoms
Explanation: First stable compound during light-independent reactions contains 3 carbon atoms.
Correct answer: 3 carbon atoms- A. Option A
- B. Option B
- C. Option C
- D. Option D
Explanation: Peak of absorption spectrum of photosyntheis is narrow and valley is broad and deep.
Correct answer: Option B- A. Same wavelength
- B. 380 - 750 nm wavelengths
- C. Different wavelengths
- D. 280 - 750 nm wavelengths
Explanation: As absorption spectra of pigments vary, they absorb light of different wavelengths.
Correct answer: Different wavelengths1289. Carotenes are mostly:
- A. Red to orange
- B. Yellow and red to orange
- C. Yellow to orange
- D. Orange and red to yellow
Explanation: According to their absorption spectra carotenes are red to orange pigments.
Correct answer: Red to orange- A. Green wavelength is reflected
- B. Green wavelength is transmitted
- C. Darker green color masks over the yellow color
- D. Green wavelength is reflected and transmitted
Explanation: Carotenoids are yellow and red to orange pigments which are masked over by green colored chlorophylls.
Correct answer: Darker green color masks over the yellow color- A. Flat
- B. Long and anchoring
- C. Square shaped
- D. Flat and square shaped
Explanation: It is porphyrin head made up of tetrapyrole rings.
Correct answer: Flat and square shaped- A. Chlorophyll - a,Chlorophyll - b
- B. Carotenoids
- C. Bacteriochlorophyll
- D. Both A and B
Explanation: Option D is correct.Both chlorophyll a and chlorophyll b are located in the thylakoid membranes of chloroplasts.
Correct answer: Both A and B- A. Few green plants and all algae
- B. All green plants and all algae
- C. All green plants and few algae
- D. Few green plants and green algae
Explanation: Option C is correct. Chlorophyll b occurs in all green plants right from bryophytes to angiosperms but it is found only in euglenoids and…
Correct answer: All green plants and few algae- A. Carbon tetrachloride
- B. Alcohol
- C. Carbon tetrachloride and alcohol
- D. Water
Explanation: Option C is correct.Chlorophylls are soluble in organic solvents, such as alcohol, ether, carbontetracholride and acetone.
Correct answer: Carbon tetrachloride and alcohol- A. Absorbing excessive light energy
- B. Dissipating excessive light energy
- C. Transferring excessive light energy to chlorophyll a
- D. Both A and B
Explanation: Option D is correct.Some carotenoids protect chlorophyll from intense light by both absorbing and dissipating excessive light energy.
Correct answer: Both A and B- A. Antenna complex
- B. Reaction complex
- C. Antenna complex and a reaction centre
- D. Primary electron acceptor
Explanation: Each photosystem consists of a light gathering antenna complex and a reaction center.
Correct answer: Antenna complex and a reaction centre- A. Cyclic phosphorylation
- B. Photophosphorylation
- C. Oxidative phosphorylation
- D. Z - scheme
Explanation: Same electrons are again and again cycled back and each time yield one ATP.
Correct answer: Cyclic phosphorylation- A. ATPs generated by light reactions
- B. NADH2 generated by light reactions
- C. FADH2 generated by light reactions
- D. Oxygen generated by light reactions
Explanation: ATP (assimilatory power) is synthesized in light reaction which is used later on in dark reaction to synthesize sugar.
Correct answer: ATPs generated by light reactions- A. Coupling of ETC by chemiosmosis
- B. Involvement of chemiosmosis
- C. Involvement of ETC
- D. Oxidative phosphorylation
Explanation: In both cyclic and non-cyclic photophosphorylation, the mechanism for ATP synthesis is chemiosmosis, the process that uses membranes to…
Correct answer: Coupling of ETC by chemiosmosis- A. Cyclic photophosphorylation
- B. Non-cyclic photophosphorylation
- C. Both cyclic and non-cyclic photophosphorylation
- D. Z-scheme
Explanation: Chemiosmosis is involved in both types of photophosphorylation.
Correct answer: Both cyclic and non-cyclic photophosphorylation