Respiration

Question 1

Name the 4 main stages in aerobic respiration

Answer 1

1. Glycolysis
2. Links reaction
3. Krebs cycle
4. ETC

Question 2

Outline the process of glycolysis

Answer 2

1. Glucose is phosphorylated to glucose phosphate by 2x ATP
2. Glucose phosphate splits into 2x triose phosphate
3. 2x TP oxidised to 2x pyruvate
   Happens in the sarcoplasm

Question 3

Outline the process of the links reaction

Answer 3

1. Pyruvate is oxidised to acetate
2. Acetate combines with coenzyme A (CoA) to form acetylcoenzyme A
   Happens in the matrix / mitochondria

Question 4

Outline the process of the Krebs cycle

Answer 4

1. Generates reduced coenzymes + ATP through a series of redox reactions
2. ATP synthesis by oxidative phosphorylation
   Happens in the cristae / mitochondria

Question 5

Name 3 products produced from the Krebs cycle other than the carbon compounds

Answer 5

1. ATP
2. reduced NAD
3. reduced FAD

Question 6

Outline the process of the ETC

Answer 6

1. Electrons released from reduced NAD / FAD undergo a series of redox reaction
2. Energy released is coupled to maintaining proton gradient
3. Oxygen acts as final electron acceptor

Question 7

How is a proton gradient established?

Answer 7

Energy released from the ETC is coupled to the active transport of protons from the mitochondrial matrix into the intermembrane space

Question 8

State the role of oxygen is aerobic respiration

Answer 8

Oxygen is the final electron acceptor in the ETC

Question 9

What happens during anaerobic respiration in animals?

Answer 9

Only glycolysis occurs to make reduced NAD + pyruvate
Turns into oxidised NAD + lactate (for further glycolysis)

Question 10

What are the pros and cons of producing lactate during anaerobic respiration?

Answer 10

+ converts reduced NAD back to oxidised NAD so glycolysis can continue
- creates acidic conditions which cause muscle fatigue

Question 11

Contrast aerobic and anaerobic respiration

Answer 11

Aerobic: Anaerobic:
more ATP produced fewer ATP produced
doesn’t produce lactate produces lactate
substrate-level + oxidative only substrate-level
phosphorylation phosphorylation

Question 12

Compare aerobic and anaerobic respiration

Answer 12

Both involve glycolysis
Both require NAD
Both produce ATP