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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1221. NADH is oxidized by
- A. ATP synthase
- B. Cytochrome B
- C. Oxygen
- D. Coenzyme Q
Explanation: NADH is oxidised by co enzyme Q and the reaction is catalyzed by NADH-ubiquinone oxidoreductase.
Correct answer: Coenzyme Q- A. Nucleus
- B. Cytosol
- C. Mitochondira
- D. Ribosomes
Explanation: Glycolisis is the 1st step of both aerobic and anaerobic respiration and takes place in cytosol of cell.
Correct answer: Cytosol- A. Red blue
- B. Yellow orange
- C. Violet red
- D. Orange red
Explanation: Chlorophyll mainly absorbs violet-blue and orange-red wavelengths. Green, yellow and indigo are least absorbed and are transmitted or…
Correct answer: Orange red- A. Energized electron
- B. Energy
- C. Uncharged electron
- D. All of these
Explanation: NADPH2 is an energy-carrying molecule produced in the first stage of photosynthesis.
Correct answer: Energized electron- A. It is a porphyrin ring or tetrapyrrole ring structure.
- B. It is flat, square and light absorbing.
- C. It is composed of carbon and nitrogen atoms with Magnesium as the central metal ion, which is coordinated with nitrogen.
- D. It is hydrophobic
Explanation: Chlorophyll is an asymmetrical molecule having a hydrophilic head made of four pyrrole rings bound to each other and forming a porphyrin.
Correct answer: It is hydrophobic- A. NADH
- B. DNA
- C. Oxygen
- D. None of these
Explanation: Option D is correct as CO2 is reduced to form carbohydrates which are not mentioned in the rest of the options.
Correct answer: None of these- A. 600 nm
- B. 650 nm
- C. 680 nm
- D. 700 nm
Explanation: PSI (Photosystem I) is a complex of chlorophyll a pigment molecules that absorbs light at a wavelength of 700 nm, which is the far-red end…
Correct answer: 700 nm- A. Ultra-Violet
- B. Blue
- C. Red
- D. None of the above options are correct
Explanation: Option A: Ultraviolet light is a different type of light and can not be seen by the naked eye hence it does not have a colour therefore…
Correct answer: Red- A. NAD
- B. ADP
- C. FADH
- D. RuBP
Explanation: The calvin cycle reactions fixes CO2 from the environment into carbohydrate molecules.
Correct answer: RuBP1230. Which of the following statements is a correct distinction between autotrophs and heterotrophs?
- A. Only heterotrophs require chemical compounds from the environment
- B. Cellular respiration is unique to heterotrophs
- C. Only heterotrophs have mitochondria
- D. Autotrophs but not heterotrophs can nourish themselves begining with nutrients that are entirely inorganic
Explanation: Autotrophs, but not heterotrophs, can nourish themselves beginning with CO2 and other nutrients that are inorganic.
Correct answer: Autotrophs but not heterotrophs can nourish themselves begining with nutrients that are entirely inorganic- A. 6.1
- B. 6.3
- C. 7.1
- D. 7.3
Explanation: The release of terminal phosphate in a single ATP molecule occurs using water, the energy released is equivalent to 7.3Kcal/mol.
Correct answer: 7.3- A. 1
- B. 6
- C. 3
- D. 0
Explanation: The equation for photosynthesis is as follows; 6CO2 + 6H2O → C6H12O6 + 6O2 Water appears on both sides of the equation because water is…
Correct answer: 0- A. It is a porphyrin ring or tetrapyrrole ring structure
- B. It is flat, square and light absorbing
- C. Composed of carbon and nitrogen atoms with magnesium as central metal ion.
- D. It is hydrophobic
Explanation: Chlorophyll molecules have a complex structure consisting of the hydrophobic tail region and hydrophilic head region because it needs to…
Correct answer: It is hydrophobic- A. Carbon fixation
- B. RUBP
- C. Reduction
- D. A and C
Explanation: Both carbon fixation and reduction are important stages in the Calvin cycle.
Correct answer: A and C- A. It occurs in darkness.
- B. It does not require light energy.
- C. It cannot occur during the daytime.
- D. It occurs more rapidly at night.
Explanation: The dark reactions of photosynthesis are also known as the Calvin cycle, and they are called "dark reactions" not because they occur in…
Correct answer: It does not require light energy.- A. Oxidation
- B. Reduction
- C. Redox
- D. None of the above
Explanation: In biological systems oxidation-reduction is a chemical reaction that usually involves the removal of the hydrogen atom from one molecule…
Correct answer: Redox- A. Chloroplast
- B. Grana
- C. Thylakoid
- D. Stroma
- E. A,B and C
Explanation: The light reactions of photosynthesis indeed take place in the thylakoid membranes within the chloroplasts of plant cells.
Correct answer: A,B and C- A. ATP sysnthesis
- B. Reduction of NADP
- C. Cyclic photophosphorylation
- D. Oxidation of the reaction center of photosystem
Explanation: The cooperation of two photosystems of the chloroplast is required for the reduction of NADP+ to NADPH, which is an important step in the…
Correct answer: Reduction of NADP- A. Pq
- B. Pc
- C. Pt
- D. Po
Explanation: Plastoquinone is an electron carrier abbreviated as Pq in plants respiratory system.
Correct answer: Pq- A. Carbon dioxide
- B. Oxygen
- C. Carotenoid
- D. Wavelength
Explanation: Absorption spectrum or photosynthesis spectrum deals with wavelengths of light absorbed by each pigment whereas the action spectrum…
Correct answer: Wavelength