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. Absorption spectrum
- B. Spectrophotometer
- C. Carotenoids
- D. Xanthophylls
Explanation: The correct answer is absorption spectrum because it is a graph that shows how much light of different wavelengths is absorbed by a…
Correct answer: Absorption spectrum- A. Plastoquinone
- B. Photolysis
- C. Plastocyanin
- D. Ferredoxin
Explanation: The correct answer is B: photolysis. During the light-dependent reactions of photosynthesis, photolysis refers to the splitting of water…
Correct answer: Photolysis- A. Antenna complex
- B. Reaction centre
- C. Photosystem
- D. ATP synthases
Explanation: The antenna complex is a light-harvesting structure made up of proteins and pigments such as chlorophyll and carotenoids that capture…
Correct answer: Antenna complex- A. Animals
- B. Plants
- C. Both A and B
- D. Synthesizing ATP during chemiosmosis
Explanation: Carotenoids perform a protective function in both plants and animals. In plants, they prevent photooxidative damage by dissipating excess…
Correct answer: Both A and B- A. 10%
- B. 20%
- C. 30%
- D. 40%
Explanation: The correct answer is 10%. Terrestrial plants, such as trees, grasses, and other land-based vegetation, contribute to about 10% of the…
Correct answer: 10%- A. 10%
- B. 30%
- C. 80%
- D. 1%
Explanation: Although a leaf absorbs a large portion of sunlight-typically around 80-90%-only a very small fraction of that light is actually converted…
Correct answer: 1%- A. Only herbivores will die
- B. Only carnivores will die
- C. No species will die
- D. Both herbivores and carnivores will die
Explanation: If green plants disappeared from the Earth, herbivores would be the first to suffer because they rely directly on plants as their primary…
Correct answer: Both herbivores and carnivores will die- A. Rubisco
- B. Ribulose
- C. Ribulose bisphosphate
- D. Cytochrome
Explanation: The correct answer is Rubisco, which stands for ribulose bisphosphate carboxylase/oxygenase.
Correct answer: Rubisco- A. It occurs during daytime
- B. It uses water with CO2
- C. It requires chlorophyll
- D. It uses oxygen
Explanation: The statement "photosynthesis uses oxygen" is incorrect because, in reality, photosynthesis produces oxygen rather than consuming it.
Correct answer: It uses oxygen- A. Mitochondria
- B. Cytoplasm
- C. Stroma of chloroplast
- D. Grana
Explanation: The conversion of light energy into chemical energy occurs in the grana of chloroplasts.
Correct answer: Grana- A. Iron
- B. Magnesium
- C. Phosphorus
- D. Nitrogen
Explanation: The molecular formulae for chlorophyll a and b are:Chlorophyll a : C55 H72 05 N4 Mg Chlorophyll b : C55 H70 06 N4 Mgchlorophyll a is…
Correct answer: Magnesium- A. Ribulose bisphosphate
- B. Hexose sugar
- C. Glycerate-3-phosphate
- D. Glyceraldehyde-9-phosphate
Explanation: In the light-independent stage of photosynthesis, also known as the Calvin cycle or dark reactions, carbon dioxide (CO2) combines with a…
Correct answer: Ribulose bisphosphate- A. Several kinds of pigments
- B. Only chlorophylls
- C. Only carotenoids
- D. Only xanthophylls
Explanation: Thylakoid membranes are integral to photosynthesis, as they house a variety of pigments.
Correct answer: Several kinds of pigments- A. First
- B. Second
- C. Third
- D. Fourth
Explanation: In glycolysis, the first step involves the phosphorylation of glucose to glucose 6-phosphate, consuming the first ATP.
Correct answer: Third- A. Phosphorylation
- B. Dephosphorylation
- C. Oxidative phosphorylation
- D. Substrate-level phosphorylation
Explanation: Photophosphorylation is the correct term for ATP formation during photosynthesis because it specifically refers to the process in which…
Correct answer: Phosphorylation- A. PS I
- B. PS II
- C. Light reaction
- D. Dark reaction
Explanation: The dark reaction, also known as the Calvin Cycle, is the second stage of photosynthesis and takes place in the stroma of the…
Correct answer: Dark reaction- A. Stomata
- B. Grana
- C. Porphyrin ring
- D. Photons
Explanation: Option A is correct. Water vapor exits and carbon dioxide (CO2) enters a leaf through tiny pores called stomata.
Correct answer: Stomata- A. Pyruvate
- B. Acetate
- C. Oxaloacetate
- D. Acetyl - CoA
Explanation: Pyruvate is produced by glycolysis in the cytoplasm, but pyruvate oxidation takes place in the mitochondrial matrix (in eukaryotes).
Correct answer: Pyruvate- A. Prokaryotes do not generate energy
- B. Prokaryotes produce energy via photosynthesis
- C. Prokaryotes have specialized mitochondria
- D. Prokaryotes generate proton gradients across their plasma membranes
Explanation: Prokaryotes generate energy through chemiosmosis, where proton gradients are formed across their plasma membranes, driving ATP synthesis.
Correct answer: Prokaryotes generate proton gradients across their plasma membranes- A. Thylakoid membrane of chloroplast
- B. Lumen of grana
- C. Stroma
- D. Outer membrane
Explanation: The correct answer is the thylakoid membrane of chloroplast. This location is integral for the light-dependent reactions of…
Correct answer: Thylakoid membrane of chloroplast