Respiration

Question 1

Where does glycolysis occur?

Answer 1

cytoplasm

Question 2

What type of respiration occurs during glycolysis?

Answer 2

anaerobic (oxygen NOT required)

Question 3

Describe the process of glycolysis

Answer 3

1) Phosphorylation of glucose to glucose phosphate
- using the inorganic phosphates from 2 ATP
2) Hydrolysed to 2 X triose phosphate
3) 2X triose phosphate become oxidised to 2X pyruvate
- 2 NAD reduced (gains hydrogen ions)
- 4 ATP regenerated
4 gained - 2 used = net production of 2 ATP

Question 4

What happens after glycolysis if no oxygen is present? (anaerobic respiration)

Answer 4

• Pyruvate is converted to lactate (animal cells, some bacteria) or ethanol (plants, yeast)
• Oxidising reduced NAD → NAD regenerated
• So glycolysis continues which needs NAD

Question 5

What happens after glycolysis is oxygen is present? (aerobic respiration)

Answer 5

• Pyruvate is actively transported out the mitochondrial matrix

Question 6

What are the 4 stages of aerobic respiration?

Answer 6

1. glycolysis
2. link reaction
3. krebs cycle
4. oxidative phosphorylation

Question 7

Where does the link reaction occur?

Answer 7

in the mitochondrial matrix

Question 8

What happens in the link reaction? (aerobic)

Answer 8

• Pyruvate is oxidised and decarboxylated to form acetate
• CO2 and reduced NAD is produced
• Acetate combines with coenzyme A → Acetyl Coenzyme A