Respiration

Question 1

What are the 4 stages of respiration?

Answer 1

Glycolysis, Link Reaction, Krebs Cycle and Oxidative Phosphorylation

Question 2

Where does glycolysis occur?

Answer 2

Cytoplasm

Question 3

Is glycolysis in aerobic or anaerobic respiration?

Answer 3

Both as it doesn’t need oxygen

Question 4

What are the 2 stages of glycolysis?

Answer 4

Phosphorylation and oxidation

Question 5

Describe the process of glycolysis

Answer 5

• glucose is phosphorylated into phosphorylated glucose by adding 2 Pi from 2 ATP molecules
• phosphorylated glucose is split into 2 triose phosphates
• triose phosphates are oxidised into pyruvate
• NAD is reduced making NADH
• 2 ATP are formed as triose phosphates lose Pi

Question 6

What is the net production of glycolysis?

Answer 6

• 2 ATP
• 2 NADH
• 2 pyruvate

Question 7

Where does the link reaction take place?

Answer 7

Mitochondrial matrix

Question 8

Describe the link reaction

Answer 8

• pyruvate is oxidised into acetate
• pyruvate loses a carbon, releasing carbon dioxide
• NAD is reduced forming NADH
• acetate binds with coenzyme A making acetylcoenzyme A
• this happens twice per glucose

Question 9

What is the net production of the link reaction?

Answer 9

• 2 carbon dioxide
• 2 NADH
• 2 acetylcoenzyme A

Question 10

Where does the krebs cycle take place?

Answer 10

Mitochondrial matrix

Question 11

Describe the krebs cycle

Answer 11

• acetylcoenzyme a combines with a 4 carbon molecule (carboxylation)
• forms a 6 carbon molecule which is then oxidised into a 4 carbon molecule
• 6 carbon molecule loses carbon releasing carbon dioxide
• ADP + Pi are reacted making ATP
• FAD is reduced forming FADH
• 3 NAD is reduced forming 3 NADH

Question 12

What is the net production of the krebs cycle?

Answer 12

• 4 carbon dioxides
• 2 ATP
• 6 NADH
• 2 FADH

Question 13

Where does oxidative phosphorylation take place?

Answer 13

Mitochondrial cristae