Cellular Respiration Practice Questions Flashcards
What is the primary purpose of cellular respiration?
a) To produce oxygen
b) To generate ATP
c) To synthesize glucose
d) To create protons
b) To generate ATP
The ultimate source of energy for cellular respiration is:
a) ATP
b) Sunlight
c) Glucose
d) Oxygen
c) Glucose
What is the main product of pyruvate oxidation?
a) Glucose
b) Acetyl-CoA
c) Lactic acid
d) GTP
b) Acetyl-CoA
The citric acid cycle completes the oxidation of glucose by:
a) Generating glucose molecules.
b) Producing water.
c) Releasing the last carbons as CO2
d) Using oxygen directly
c) Releasing the last carbons as CO2
ATP synthase generates ATP using:
a) Substrate-level phosphorylation
b) Proton flow through it
c) Direct oxidation of glucose
d) Carbon fixation
b) Proton flow through it
What happens to electrons as they move down the ETC?
a) They gain energy.
b) Their energy remains constant.
c) They lose energy.
d) They are converted into protons.
c) They lose energy.
Substrate-level phosphorylation directly generates ATP by:
a) Oxidizing NADH.
b) Transferring a phosphate group from a substrate to ADP.
c) Using proton motive force.
d) Reducing oxygen.
b) Transferring a phosphate group from a substrate to ADP.
What is chemiosmosis?
a) Movement of protons across a membrane down their concentration gradient
b) Synthesis of glucose molecules
c) Breakdown of pyruvate into acetyl-CoA
d) Direct use of ATP for transport
a) Movement of protons across a membrane down their concentration gradient
Fermentation occurs:
a) Only in the presence of oxygen
b) To regenerate NAD+ for glycolysis
c) During the citric acid cycle
d) In the electron transport chain
b) To regenerate NAD+ for glycolysis
Lactic acid buildup occurs during:
a) The citric acid cycle
b) Oxidative phosphorylation
c) Anaerobic conditions in muscles
d) Chemiosmosis
c) Anaerobic conditions in muscles
Which organism is commonly associated with alcoholic fermentation?
a) Bacteria
b) Yeast
c) Human cells
d) Fungi
b) Yeast
What is a defense mechanism against reactive oxygen species (ROS)?
a) NADH synthesis
b) Enzymes like catalase and antioxidants
c) Proton gradient formation
d) Glucose storage
b) Enzymes like catalase and antioxidants
Which one of the below is a major mechanism that regulates cellular respiration?
a) ATP hydrolysis
b) Feedback inhibition of enzymes
c) Direct control of ETC proteins
d) Oxygen supply control
b) Feedback inhibition of enzymes
Why is the stepwise oxidation of glucose in cellular respiration more efficient than
direct combustion?
a) It uses oxygen more effectively.
b) It uses the energy in high-energy electrons gradually.
c) It prevents the formation of reactive oxygen species (ROS).
d) It avoids the production of carbon dioxide.
b) It uses the energy in high-energy electrons gradually
Oxygen is essential in cellular respiration because it:
a) Directly produces ATP in glycolysis.
b) Serves as the terminal electron acceptor in the ETC.
c) Pumps protons into the intermembrane space.
d) Breaks glucose into pyruvate.
b) Serves as the terminal electron acceptor in the ETC.
