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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- A. Intermembrane space
- B. Outer membrane
- C. Matrix
- D. Inner membrane
Explanation: ATP synthase is located in the inner mitochondrial membrane of the mitochondrion.
Correct answer: Inner membrane- A. Glycolysis
- B. The oxidation of pyruvates
- C. Kreb's cycle
- D. All of these
Explanation: FADH2 (flavin adenine dinucleotide) is produced during cellular respiration, specifically in the citric acid cycle (also known as the…
Correct answer: Kreb's cycle- A. HMP
- B. ETS
- C. Kreb's cycle
- D. None of these
Explanation: NADPH (reduced nicotinamide adenine dinucleotide phosphate) is more directly associated with other pathways, such as the pentose phosphate…
Correct answer: HMP- A. FAD
- B. FADH
- C. FADH2
- D. NADH2
Explanation: Succinate is oxidized to fumarate in the citric acid cycle, and during this process, FAD is reduced to form FADH2.
Correct answer: FADH2245. The spent energy in the form of ADP is regenerated by mitochondria into which of the following?
- A. AMP
- B. ATP
- C. ADP
- D. All of these
Explanation: The correct answer is ATP. Mitochondria are known as the powerhouse of the cell because they convert ADP into ATP through cellular…
Correct answer: ATP- A. Light dependent reaction
- B. Light independent reaction
- C. Both of these
- D. None of above
Explanation: The stage of photosynthesis where ATP (adenosine triphosphate) and NADPH (nicotinamide adenine dinucleotide phosphate) are converted to…
Correct answer: Light independent reaction- A. It combines with acetyl-CoA at the start of the Krebs cycle
- B. It plays no role
- C. It is given off as a by-product during the oxidation of pyruvates
- D. It is the final electron acceptor at the end of the electron transport chain
Explanation: During oxidative phosphorylation, oxygen serves as the final electron acceptor in the electron transport chain.
Correct answer: It is the final electron acceptor at the end of the electron transport chain- A. H2O + CO2
- B. Methyl alcohol + CO2
- C. Methyl alcohol + water
- D. Ethyl alcohol + CO2
Explanation: Fermentation in yeast, particularly alcoholic fermentation, produces ethanol (alcohol) and carbon dioxide as the main products.
Correct answer: Ethyl alcohol + CO2- A. Stroma and grana of the chloroplast, respectively
- B. Grana and stroma of the chloroplast respectively
- C. Grana only
- D. Stroma only
Explanation: The light reactions occur in the thylakoid membra,nes, while the dark reactions (Calvin Cycle) ,take place in the stroma of the…
Correct answer: Stroma and grana of the chloroplast, respectively- A. Nucleus
- B. Mitochondria
- C. Golgi complex
- D. Cytoplasm
Explanation: Glycolysis, the first step of aerobic respiration, which results in the formation of two molecules of pyruvate from one molecule of…
Correct answer: Cytoplasm- A. Stroma to Lumen
- B. Cytoplasm to Stroma
- C. Lumen to Stroma
- D. Stroma to cytoplasm
Explanation: Chemiosmosis is the process whereby protons move down their electrochemical gradient, i.e., from a region of higher concentration to a…
Correct answer: Lumen to Stroma- A. Three
- B. Two
- C. Four
- D. One
Explanation: Two ATP molecules are used to phosphorylate glucose; the first is used to convert glucose into glucose-6-phosphate, while the second is…
Correct answer: Two- 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…
Correct answer: Ribulose bisphosphate- A. 660 nm
- B. 680 nm
- C. 440 nm
- D. 700 nm
Explanation: Since chlorophyll absorbs maximum energy from the blue and red wavelengths, blue light is absorbed more for photosynthesis than any other…
Correct answer: 440 nm- A. Stroma
- B. Grana
- C. Thylakoid
- D. Outer membrane
Explanation: The correct answer is the stroma. The stroma is the site of the Calvin cycle, the series of light-independent reactions where carbon…
Correct answer: Stroma- A. FADH2
- B. ATP
- C. NADH
- D. GTP
Explanation: ATP is indeed the most energy-rich compound in cellular metabolism. ATP (adenosine triphosphate) is the cell's primary energy currency.
Correct answer: ATP- A. 3
- B. 6
- C. 2
- D. 1
Explanation: The Calvin cycle, also referred to as the C3 cycle, processes CO2 into carbohydrates in the stroma of chloroplasts.
Correct answer: 1- A. Yellow
- B. Red
- C. Orange
- D. Green
Explanation: Xanthophylls are a class of oxygen-containing carotenoid pigments primarily responsible for the yellow color observed in many flowers…
Correct answer: Yellow- A. Thylakoid
- B. Grana
- C. Stroma
- D. All of these options are correct
Explanation: The dark reaction or light-independent reaction occurs in the stroma of the chloroplast.
Correct answer: Stroma- A. Green plants
- B. Green algae
- C. Animals
- D. Both Options A and B are correct
Explanation: There are four types of chlorophyll: chlorophyll a, found in all higher plants, algae, and cyanobacteria; chlorophyll b, found in higher…
Correct answer: Both Options A and B are correct