A-Level Biology Unit 4: Chapter 4
Aerobic Respiration Common Exam Questions and Model Answers
General Questions:
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Tick boxes in table to show if NAD / ATP / CO2 produced in Glycolysis / Link / Krebs and location of
stages
Write in names of substances / how many C-atoms in the substance
Label on mitochondria diagram where stages occur (for ETC label the inner membrane)
Experiment done on isolated mitochondria. Why was glucose not used as a respiratory substrate?
1. Glucose is broken down during glycolysis in cytoplasm;
2. Glucose cannot cross mitochondrial membrane;
How is oxygen used? (question comes in various forms)
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Oxygen used as final/terminal (electron) acceptor in the electron transport chain
Electrons cannot be passed along electron transport chain if there is no oxygen to accept them
Therefore used to generate ATP
Accepts H+ to form water
Respirometer/Manometer experiment. Why did the air bubble move (has come up twice)
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Oxygen used in respiration
Carbon dioxide (given out) is absorbed by solution/potassium hydroxide;
Decrease in volume / pressure (inside flask);
Describe the part played by the inner membrane of a mitochondrion in producing ATP.
 Electrons transferred down electron transport chain;
 Provide energy to take protons/H+ into space between membranes;
 Protons/H+ pass back, through membrane/into matrix/through ATPase;
 Energy used to combine ADP and phosphate/to produce ATP;
In which step of respiration is carbon dioxide produced
Krebs / Link reaction
How would temperature affect respiration (be specific in answer whether Q refers to increased or
decreased temp)
Enzyme controlled; kinetic energy; collisions between E and S; number of E-S complexes formed
Describe how ATP is made in mitochondria
1. Substrate level phosphorylation / ATP produced in Krebs cycle;
2. Krebs cycle/link reaction produces reduced NAD/reduced FAD;
3. Electrons released from reduced NAD/FAD;
4. (Electrons) pass along carriers/through electron transport chain/through series of redox reactions;
5. Energy released;
6. ADP/ADP + Pi;
7. Protons move into intermembrane space;
8. ATP synthase;