Free Cellular Respiration MCQs with Answers
182 Cellular Respiration 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 releases energy from glucose through glycolysis, the link reaction, the Krebs cycle and the electron transport chain, producing ATP. The pathway differs in oxygen availability: aerobic respiration uses oxygen and yields more ATP, while anaerobic respiration produces much less ATP and forms lactic acid in muscles or ethanol and carbon dioxide in yeast.
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182 questions · page 7 of 10
- A. 25%
- B. 10%
- C. 5%
- D. 1%
Explanation: Only about 1% of the sunlight reaching Earth is captured by green plants and converted into chemical energy through photosynthesis.
Correct answer: 1%- A. Cytohrome c
- B. Cytochrome a
- C. Cytochrome a3
- D. Cytochrome b
Explanation: Cytochrome c is a mobile electron carrier in the electron transport chain and transfers electrons between respiratory complexes, making it…
Correct answer: Cytohrome c123. Interconversion of carbohydrates proteins and lipids in living cells are an example of____________?
- A. Coordinated catabolic activities
- B. Coordinated anabolic activities
- C. Both A and B
- D. Any one
Explanation: Cells interconvert carbohydrates, proteins and lipids through linked metabolic pathways, so both breakdown reactions and synthesis…
Correct answer: Both A and B- A. Glyceraldehydes
- B. Dihydroxy acetone
- C. Both of these
- D. None of these
Explanation: Glyceraldehyde-3-phosphate and dihydroxyacetone phosphate are three-carbon intermediates found in pathways of both photosynthesis and…
Correct answer: Both of these- A. As an energy currency of the cell
- B. As a coenzyme
- C. Both a and b
- D. None of these
Explanation: ATP stores usable chemical energy in its phosphate bonds and transfers that energy to cellular processes, so it is called the energy…
Correct answer: As an energy currency of the cell- A. Release of CO2
- B. Reduction of NAD
- C. Formation of ATP
- D. Production of ethanol from acetaldehyde
Explanation: In alcoholic fermentation, acetaldehyde accepts hydrogen from reduced NAD and is converted into ethanol, regenerating NAD for glycolysis.
Correct answer: Production of ethanol from acetaldehyde127. How many moles of carbon dioxide are produced by complete oxidation of one mole of puruvic acid?
- A. 1
- B. 2
- C. 3
- D. 6
Explanation: One pyruvic acid molecule has three carbon atoms, and complete oxidation releases all three as carbon dioxide: one during the link…
Correct answer: 3- A. Metabolic reactions
- B. Catabolic reactions
- C. Anabolic reactions
- D. None of these
Explanation: Anabolic reactions build complex molecules from simpler substances and usually require an input of energy, such as the formation of…
Correct answer: Anabolic reactions129. In which of the following location enzymes controlling cellular respiration are present____________?
- A. Nucleus
- B. Chlorophast
- C. Milochondria
- D. Ribosome
Explanation: In eukaryotic cells, the major enzymes controlling aerobic cellular respiration are located in mitochondria, especially the matrix and…
Correct answer: Milochondria- A. AMP
- B. ADP
- C. ATP
- D. All of these
Explanation: Mitochondria regenerate ATP from ADP by adding inorganic phosphate during oxidative phosphorylation: ADP + phosphate forms ATP.
Correct answer: ATP- A. C-H bond
- B. C-O bond
- C. C-N bond
- D. P-O-C bond
Explanation: C-H bonds in organic food molecules contain potential chemical energy, which is released stepwise during cellular respiration and…
Correct answer: C-H bond- A. Peroxisome
- B. Glyoxisome
- C. Lysosome
- D. Golgi bodies
Explanation: Glyoxisomes contain enzymes of the glyoxylate cycle, which allows plant cells to convert fatty-acid products into succinate and other…
Correct answer: Glyoxisome133. In lactic acid fermentation, pyruvic acid converts into lactic acid by accepting electrons from:
- A. NAD+
- B. NADP+
- C. NADH
- D. NADPH
Explanation: Lactic Acid Fermentation: In this anaerobic process, pyruvic acid is reduced to lactic acid.
Correct answer: NADH- A. Citrate
- B. Malate
- C. Fumarate
- D. Succinate
Explanation: The Krebs cycle, also known as the citric acid cycle, begins with the condensation of Acetyl Co-A and Oxaloacetate to form citrate.
Correct answer: Citrate- A. The reduction of hydrogen carriers
- B. The oxidation of glyceraldehyde 3-phosphate
- C. Accepting electrons at the end of the electron transport chain
- D. Maintaining an oxygen concentration gradient in mitochondria
Explanation: The correct answer is Option C: accepting electrons at the end of the electron transport chain.
Correct answer: Accepting electrons at the end of the electron transport chain- A. ATP→ADP
- B. ADP→ATP
- C. NAD+→NADH
- D. NADH→NAD+
Explanation: During the preparatory phase of glycolysis, 2 molecules of ATP are invested to convert glucose to Glucose-6-phosphate and…
Correct answer: ATP→ADP- A. C6H12O6 → 2 C3H6O3
- B. C6H12O6 + 6 O2 → 6 CO2 + 6 H2O
- C. C6H12O6 → 2 C2H5OH + 2 CO2
- D. C6H12O6 → 6 CO2 + 6 H2O
Explanation: The correct equation for the conversion of glucose into lactic acid during anaerobic respiration is C6H12O6 → 2 C3H6O3.
Correct answer: C6H12O6 → 2 C3H6O3- A. Breakdown of pyruvic acid into ethanol
- B. Formation of pyruvic acid from glucose
- C. Breakdown of pyruvic acid into lactic acid
- D. Release of carbon dioxide gas from pyruvic acid
Explanation: The correct answer is the formation of pyruvic acid from glucose. This step is known as glycolysis, which is the initial stage of both…
Correct answer: Formation of pyruvic acid from glucose- A. Glycolysis
- B. Krebs cycle
- C. Pyruvate oxidation
- D. Electron transport chain
Explanation: The correct answer is the Krebs cycle.During cellular respiration, NADH and FADH2 are primarily produced in the Krebs cycle.
Correct answer: Krebs cycle- A. A.
- B. B.
- C. C.
- D. D.
Explanation: The correct answer is the formation of pyruvic acid from glucose. This step is known as glycolysis, which is the initial stage of both…
Correct answer: B.