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. Cytoplasm
- B. Mitochondria
- C. Nucleus
- D. Cell membrane
Explanation: The enzymes involved in the chemical reactions of glycolysis are located in the cytoplasm.
Correct answer: Cytoplasm- A. Acetyl coenzyme A
- B. ATP
- C. Pyruvate
- D. Reduced NAD
Explanation: The correct answer is ATP. During glycolysis, ATP is initially consumed to provide the energy needed to start the breakdown of glucose.
Correct answer: ATP- A. Water
- B. Carbon dioxide
- C. Oxygen in air
- D. Both from water and carbon dioxide
Explanation: Carbon dioxide (CO2) is one of the reactants in photosynthesis. It is taken in by the plant from the atmosphere through tiny pores called…
Correct answer: Carbon dioxide- A. Fixes carbon dioxide
- B. Works only in the presence of light
- C. Traps light energy
- D. Synthesis of ATP
Explanation: The second set of reactions in photosynthesis is known as the light-independent reactions, or the Calvin Cycle.
Correct answer: Fixes carbon dioxide- A. Hydrolysis
- B. Hemolysis
- C. Plasmolysis
- D. Photolysis
Explanation: Photolysis, also known as photodissociation or photodecomposition, refers to the process by which a chemical compound is broken down or…
Correct answer: Photolysis- A. Joining of 3 carbon atoms to from glucose
- B. lonization of water
- C. Excitement of an electron of chlorophyll by a photon of light
- D. Formation of ATP
Explanation: Light Absorption: Chlorophyll molecules, organised into photosystems in the thylakoid membranes, capture photons of light.
Correct answer: Excitement of an electron of chlorophyll by a photon of light- A. Red light
- B. Green light
- C. Blue light
- D. Violet light
Explanation: The correct answer is green light because it is mostly reflected, not absorbed, by plants, making it the least effective in…
Correct answer: Green light- A. ATP
- B. ATP and NADPH2
- C. NADP+
- D. ATP, NADP and CO2
Explanation: Adenosine Triphosphate, commonly known as ATP, is a molecule that plays a crucial role in the transfer of energy within cells.
Correct answer: ATP- A. 50%
- B. 1%
- C. 10%
- D. 75%
Explanation: The percentage of light energy fixed in photosynthesis is generally around 1%, which implies that the overall productivity of the…
Correct answer: 1%- A. Pigment System I
- B. Pigment System II
- C. Plastocyanin
- D. Cytochrome B6
Explanation: Photo-oxidation of water in photosynthesis is in association of pigment System II. "The explanation for this question will be added soon!".
Correct answer: Pigment System II- A. Stroma
- B. Grana
- C. On Surface of mitochondria
- D. Inner membrane of mitochondria
Explanation: Grana are structures within chloroplasts that consist of stacks of thylakoid discs.
Correct answer: Grana- A. Cytochrome b
- B. Cytochrome a
- C. Cytochrome a3
- D. Cytochrome c
Explanation: Complex IV (Cytochrome c Oxidase) is the final enzyme complex in the electron transport chain.
Correct answer: Cytochrome a3- A. Production of ATP
- B. Photolysis
- C. Formation of NADPH
- D. Excitation of electrons by light
Explanation: During the light reactions of photosynthesis, excitation of electrons by light and production of ATP occur in both cyclic and non-cyclic…
Correct answer: Production of ATP- A. Oxygen
- B. ATP
- C. Glucose
- D. NADPH
Explanation: During cyclic photophosphorylation, energy is obtained in the form of ATP.
Correct answer: ATP- A. Chloroplast
- B. Mitochondria
- C. Glyoxysomes
- D. Cytoplasm
Explanation: In the stroma of the chloroplast, carbon dioxide is fixed into organic molecules using ATP and NADPH produced during the light reactions.
Correct answer: Chloroplast- A. Stroma
- B. Thylakoid
- C. Grana
- D. Cytoplasm
Explanation: The dark reaction of photosynthesis, also known as the Calvin cycle, takes place in the stroma of the chloroplast.
Correct answer: Stroma- A. CO2 is reduced to organic compound
- B. Chlorophyll is activated
- C. 6C sugar is broken down into 3C sugar
- D. Photolysis
Explanation: The dark reactions occur in the stroma of the chloroplast and are also known as the Calvin cycle.
Correct answer: CO2 is reduced to organic compound- A. Dark Reaction
- B. Photosystem I
- C. Photosystem II
- D. Photolysis
Explanation: The correct answer is the dark reaction, which is also referred to as the Calvin cycle.
Correct answer: Dark Reaction- A. Ribulose 1,5 bisphosphate carboxylase
- B. Triose phosphate dehydrogenase
- C. Cytochrome oxidase
- D. Hexokinase
Explanation: RuBisCO is the correct enzyme because it catalyses the first step of the Calvin cycle by fixing carbon dioxide to…
Correct answer: Ribulose 1,5 bisphosphate carboxylase- A. Oxygen
- B. Carbon dioxide
- C. Light
- D. Chlorophyll
Explanation: The correct answer is oxygen. While oxygen is involved in the process of photorespiration, it is not a primary factor that limits…
Correct answer: Oxygen