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 18 of 69
341. 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 beginning with entirely inorganic nutrients
Explanation: Autotrophs, but not heterotrophs, can nourish themselves beginning with CO2 and other inorganic nutrients.
Correct answer: Autotrophs, but not heterotrophs, can nourish themselves beginning with entirely inorganic nutrients- A. ATP ligase
- B. ATP kinase
- C. ATP synthase
- D. ATP dehydrogenase
Explanation: ATP synthase is the enzyme that makes ATP by chemiosmosis. It allows protons to pass through the membrane and uses the free energy…
Correct answer: ATP synthase- A. 20 kcal/mol
- B. 12kcal/mol
- C. 3.5kcal/mol
- D. 7.3kcal/mol
Explanation: The release of terminal phosphate in a single ATP molecule occurs using water; the energy released is equivalent to 7.3 kcal/mol.
Correct answer: 7.3kcal/mol- A. 7 kcal
- B. 8 kcal
- C. 7.5 kcal
- D. 7.3 kcal
Explanation: The hydrolysis of one ATP molecule releases 7.3 kcal/mol of energy.(∆G = −7.3 kcal/mol of energy)
Correct answer: 7.3 kcal- A. 1
- B. 6
- C. 3
- D. 0
Explanation: In the process of photosynthesis, water (H2O) is split during the light-dependent reactions to provide electrons, protons (H+), and oxygen…
Correct answer: 0- A. Bacteria
- B. Algae
- C. Protonema
- D. Cyanobacteria
Explanation: This option is correct. The answer is bacteria. The Van Niel hypothesis was based on the study and investigations on bacteria.
Correct answer: Bacteria- A. Stroma
- B. Cytosol
- C. Mitochondria
- D. Thylakoid/Grana
Explanation: The light-dependent reactions use light energy to make two molecules needed for the next stage of photosynthesis: the energy storage…
Correct answer: Thylakoid/Grana- A. Phosphoglycerate
- B. Phosphoenol pyruvate
- C. Glycerate
- D. Glycine
Explanation: The C4 pathway initiates with a molecule called phosphoenolpyruvate (PEP) which is a 3-carbon molecule.
Correct answer: Phosphoenol pyruvate- A. ATP is hydrolysed and NADP is reduced
- B. ATP is hydrolysed and NADPH is oxidized
- C. ATP is synthesized and NADP is reduced
- D. ATP is synthesized and NADPH is oxidized
Explanation: During photophosphorylation, which is part of the light-dependent reactions of photosynthesis, ATP is synthesized through a process known…
Correct answer: ATP is synthesized and NADP is reduced- A. Inorganic
- B. Cationic
- C. Anionic
- D. Organic
Explanation: Chlorophyll is considered an organic molecule as it contains carbon atoms and is part of larger organic molecules found in plants.
Correct answer: Organic- A. Carbon fixation
- B. RUBP regeneration
- C. Reduction
- D. Carbon fixation,Reduction, and RUBP regeneration
Explanation: The correct answer is Carbon fixation,Reduction,and RUBP regeneration. The Calvin cycle involves three crucial stages: Carbon fixation…
Correct answer: Carbon fixation,Reduction, and RUBP regeneration- A. 3
- B. 2
- C. 4
- D. 1
Explanation: 1 NADH molecule is produced at each of the following stages of a single Krebs cycle; therefore, 3 NADH molecules in total.1.
Correct answer: 3- A. Stroma
- B. Chloroplast envelope
- C. Thylakoid membranes
- D. The intergrana
Explanation: The thylakoid membrane systems of cyanobacteria and of plant and algal chloroplasts contain the specialized photosystems, photosystem I…
Correct answer: Thylakoid membranes- A. Acetyl coA
- B. Alcohol
- C. Lactic acid
- D. All of these
Explanation: Muscle cells perform lactic acid fermentation (a form of anaerobic respiration) during vigorous exercise due to decrease amount or absence…
Correct answer: Lactic acid- A. Respiration
- B. Calvin cycle
- C. Oxidative phosphorylation
- D. Chemiosmosis
Explanation: Oxidative phosphorylation is the process by which ATP synthesis is coupled to the movement of electrons through the mitochondrial electron…
Correct answer: Oxidative phosphorylation- A. Organic
- B. Energy-poor
- C. Energy-rich
- D. Reduced
Explanation: During photosynthesis, energy-rich carbohydrates are formed from inorganic compounds like carbon dioxide and water that have much less…
Correct answer: Energy-poor- A. 0.02-0.03%
- B. 0.03-0.04%
- C. 0.04-0.05%
- D. 0.05-0.06%
Explanation: The Earth's atmosphere contains about 0.03-0.04 % carbon dioxide.Hence, B is the correct option.
Correct answer: 0.03-0.04%- A. 40
- B. 10
- C. 20
- D. 30
Explanation: 90% of total photosynthesis is carried out by aquatic plants. Most of them are marine algae, which account for nearly 80%.
Correct answer: 10- A. ATP
- B. NADPH
- C. Oxygen
- D. All of these options are correct
Explanation: During the non-cyclic electron flow of photosynthesis, which occurs in the thylakoid membranes of the chloroplasts, light energy is used…
Correct answer: All of these options are correct- A. Light reaction
- B. Dark reaction
- C. Aerobic respiration
- D. Anaerobic respiration
Explanation: The dark reaction, or light-independent reaction, occurs in the stroma of the chloroplast and involves the fixation of carbon dioxide…
Correct answer: Dark reaction