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. 6
- B. 2
- C. 4
- D. 8
Explanation: The products in one turn of the Calvin cycle are 2 glyceraldehyde-3-phosphate (G3P) molecules, 3 ADP, and 2 NADP+.Therefore for every 3…
Correct answer: 6- A. Chlorophyll e
- B. Chlorophyll b
- C. Chlorophyll c
- D. All of these options
Explanation: Bacteria use bacteriochlorophylls in photosynthesis without the production of energy.
Correct answer: All of these options- A. Orange blue
- B. Red
- C. Blue
- D. Green
Explanation: Green light is not as efficiently absorbed by chlorophyll, the pigment responsible for photosynthesis in plants, as compared to red and…
Correct answer: Green- A. Hydrophilic
- B. Hydrophobic
- C. Both of these
- D. None of these
Explanation: The part of the chlorophyll molecule that is embedded in the core of the thylakoid membrane is the hydrophobic tail.
Correct answer: Hydrophobic- A. Glycolysis
- B. Photosynthesis
- C. Respiration
- D. Krebs Cycle
Explanation: The correct answer is Photosynthesis. Photosynthesis is an endothermic process, meaning it requires energy input from sunlight to convert…
Correct answer: Photosynthesis- A. Chlorophyll
- B. Protein synthesis
- C. Glucose metabolism
- D. All of these
Explanation: Magnesium is essential for the synthesis of chlorophyll, the pigment responsible for capturing light energy in photosynthesis.
Correct answer: Chlorophyll- A. 1
- B. 2
- C. 3
- D. 6
Explanation: The Calvin Cycle, the light-independent reactions of photosynthesis, produces three molecules of glyceraldehyde-3-phosphate (G3P) for…
Correct answer: 1- A. Pq
- B. Pc
- C. Pt
- D. Po
Explanation: Plastocyanin (Pc) is a copper-containing protein that plays a crucial role in the electron transport chain (ETC) during photosynthesis in…
Correct answer: Pc369. The Calvin cycle is:
- A. Inhibited by light
- B. Dependent upon light
- C. Independent of light
- D. Supported by light
Explanation: The Calvin cycle, also known as the dark reactions or light-independent reactions of photosynthesis, does not directly depend on light.
Correct answer: Independent of light- A. Blue
- B. Red
- C. Orange
- D. Violet
Explanation: Red causes the highest rate of photosythesis as it powers the synthesis of ATP and NADPH.
Correct answer: Red- A. Oxidation
- B. Reduction
- C. Redox
- D. None of the above options are correct
Explanation: Cellular respiration is a redox (reduction-oxidation) process. Redox reactions involve the transfer of electrons from one molecule to…
Correct answer: Redox- A. Acetyl CoA
- B. Alcohol
- C. Lactic acid
- D. All of these options are correct
Explanation: In yeast and other microorganisms during fermentation, pyruvate is typically broken down into ethanol (ethyl alcohol) and carbon dioxide…
Correct answer: Alcohol- A. ATP synthase
- B. Globulin
- C. Rubisco
- D. NADH dehydrogenase
Explanation: The reaction between carbon dioxide (CO2) and ribulose-1,5-bisphosphate (RuBP) is catalyzed by the enzyme ribulose-1,5-bisphosphate…
Correct answer: Rubisco- A. UV light
- B. Visible light
- C. Both Options A and B are correct
- D. None of these options is correct
Explanation: The radiations most important to life are typically referred to as "biologically relevant" or "biologically important" radiations.
Correct answer: Visible light- A. 5
- B. 6
- C. 8
- D. 4
Explanation: Citrate, the first compound formed in the Krebs cycle (also known as the citric acid cycle or tricarboxylic acid cycle), has six carbon…
Correct answer: 6- A. 300-700
- B. 350-750
- C. 380-750
- D. 390-790
Explanation: Visible light, which ranges from approximately 380 to 750 nanometers (nm) in wavelength, is indeed crucial to life on Earth.
Correct answer: 380-750- A. ATP
- B. NADH
- C. Carbon dioxide
- D. All of the above
Explanation: During photosynthesis, carbon dioxide (CO2) is utilized in the process of sugar production.
Correct answer: Carbon dioxide- A. NADP Oxidase
- B. NADP reductase
- C. ATP synthase
- D. Both A and B
Explanation: The transfer of electrons from ferredoxin (Fd) to NADP+ during the light-dependent reactions of photosynthesis is facilitated by the…
Correct answer: NADP reductase- A. NADH and FADH
- B. NADP and FADP
- C. ATP
- D. ATP, NADH and FADH2
Explanation: When acetyl CoA undergoes complete oxidation in the citric acid cycle (also known as the Krebs cycle or tricarboxylic acid cycle), it…
Correct answer: ATP, NADH and FADH2- A. C4 plants
- B. Heterotrophs
- C. C3 plants
- D. CAM plants
Explanation: C3 plants have the disadvantage that in hot dry conditions their photosynthetic efficiency suffers because of a process called…
Correct answer: C3 plants