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 64 of 69
- A. Chlorophyll - b
- B. Chlorophyll - a
- C. Bacteriochlorophyll
- D. Carotenoids
Explanation: The correct answer is Option B: Chlorophyll - a. Chlorophyll a is fundamental to the photosynthetic process across all photosynthetic…
Correct answer: Chlorophyll - a- A. Alpha ketoglutaric acid
- B. Citric acid
- C. Glyceric acid
- D. Acetyl-CoA
Explanation: Before entering the Krebs cycle, pyruvate is converted into acetyl-CoA through the link reaction, where it is decarboxylated and oxidized.
Correct answer: Acetyl-CoA- A. Cytochrome a
- B. Oxygen
- C. Cytochrome a3
- D. Cytochrome c
Explanation: In the electron transport chain, oxygen serves as the final electron acceptor.
Correct answer: Oxygen- A. 680 nm
- B. 100 nm
- C. 700 nm
- D. 670 nm
Explanation: This wavelength of light is red and red colour light is highly absorbed because it carries out most of the synthetic reaction.
Correct answer: 680 nm- A. Carbon tetrachloride (CCl4)
- B. Alcohol
- C. Organic Solvents
- D. None of these
Explanation: Chlorophyll is a hydrophobic molecule, meaning it does not dissolve in water, a polar solvent.
Correct answer: None of these- A. Bioenergetics
- B. Laws of thermodynamics
- C. Laws of thermochemistry
- D. Laws of chemical energetics
Explanation: The correct answer is the laws of thermodynamics. These laws provide the essential framework for understanding how energy is conserved and…
Correct answer: Laws of thermodynamics- A. 0.2%
- B. 0.15%
- C. 0.05%
- D. 1%
Explanation: 1% is the amount of percentage the leaf absorbs the sunlight.
Correct answer: 1%- A. Fructose-6-Phosphate
- B. Glucose-6-Phosphate
- C. Fructose-1,6 biphosphate
- D. Dihydroxyacetone phosphate
Explanation: A. Glucose-6 phosphate is converted into its isomer fructose -6-phosphate, by an isomerase enzyme.C.
Correct answer: Glucose-6-Phosphate- A. T.W.Engleman
- B. Malleus
- C. T.W.Inws
- D. W.Stapes
Explanation: The first action spectrum was made by T. W. Engelmann, who split light into its components by the prism and then illuminated Cladophora…
Correct answer: T.W.Engleman- A. C6H12O6 + 6O2
- B. (CH2O)n + H2O + 2S
- C. C6H12O6 + 6O2 + H2O + Energy
- D. C6H12O6 + 6O2 + 6 H2O
Explanation: A.6 molecules of water are also released. B.These are the products of photosynthetic bacteria which use H2S instead of water and release…
Correct answer: C6H12O6 + 6O2 + 6 H2O1271. Chlorophyll consists of:
- A. A head of phytol and tail of four pyrrole rings
- B. A head of linked carbons and tail of four pyrrole rings
- C. A head of four pyrrol rings and tail of linked nitrogen
- D. A head of four pyrrol rings and a phytol tail
Explanation: A chlorophyll molecule has two main parts; one flat, light absorbing hydrophilic head and the other long, anchoring, hydrophobic…
Correct answer: A head of four pyrrol rings and a phytol tail- A. Chl.a has different types while Chl.b has single type
- B. Chl.a have functional group -CH3 but Chl.b has CHO
- C. Chl.a is necessary pigments but Chl.b is accessory pigments
- D. Chl.a is present in antenna complex while Chl.b is in reaction center
Explanation: Chlorphyll b is not found in reaction center.
Correct answer: Chl.a is present in antenna complex while Chl.b is in reaction center1273. PS-I is named as it:
- A. Absorbs wavelength of 680 nm
- B. Discovered earlier than PS-II
- C. Absorbs wavelength of 700 nm
- D. Slightly located upward than PS-II
Explanation: Photosynthetic pigments are organized into clusters, called photosystems. There are two photosystems found in plants, PS-I and PS-II.
Correct answer: Discovered earlier than PS-II- A. 1
- B. 4
- C. 2
- D. 6
Explanation: Each photon of light is able to excite a singlc electron during light reactions of photosynthesis.
Correct answer: 1- A. Interior space of thylakoid
- B. Outside the thylakoid membrane
- C. Into the stroma
- D. At ATP synthase complex
Explanation: Water splits during photosynthesis in the interior space of thylakoid.
Correct answer: Interior space of thylakoid- A. It absorbs photons into PS-I
- B. It is a long pathway
- C. It produce ATP
- D. Carbon dioxide fixation
Explanation: Carbon dioxide fixation does not take place in light dependent phase of photosynthesis; rather its fixation occurs in light independent…
Correct answer: Carbon dioxide fixation- A. Glycolysis
- B. The electron transport system
- C. Kerbs cycle
- D. Fermentation
Explanation: The cyclic reactions of Krebs cylce produce both NADH and FADH2, while in glycolysis, only NADH is produced.
Correct answer: Kerbs cycle- A. Pyruvate decarboxylase
- B. Phosphofructokinase
- C. Glucokinase
- D. Pyruvate phosphatases
Explanation: When excess NADH accumulates, the enzymes that produce NADH from NAD+ will be inhibited.
Correct answer: Pyruvate decarboxylase- A. Option A
- B. Option B
- C. Option C
- D. Option D
Explanation: In a photosynthesizing cell exposed to high light intensity and low carbon dioxide concentration, the rate of photosynthesis may be…
Correct answer: Option A- A. Acetyle coenzyme A
- B. Ribulose bisphosphate
- C. Fructose 1, 6-bisphosphate
- D. Triose phosphate
Explanation: Triose phosphate refers to a class of three-carbon sugar phosphates that play critical roles in cellular metabolism, particularly in…
Correct answer: Triose phosphate