IDk

Question 1

Outline the 4 steps of respiration

Answer 1

1. Glycolysis
2. Link reaction
3. Kreb’s cycle
4. Oxidative phosphorylation

Question 2

Where does glycolysis take place?

Answer 2

Cytoplasm

Question 3

Where does the link reaction take place?

Answer 3

Mitochondrial matrix

Question 4

Where does the krebs cycle take place?

Answer 4

Mitochondrial matrix

Question 5

Where does oxidative phosphorylation take place?

Answer 5

Mitochondrial inner membrane cristae

Question 6

Explain what happens in glycolysis

Answer 6

1. Glucose (6C) is phosphorylated to glucose phosphate (6C), using 2 ATP, releasing 2 ADP.
2. From this, 2 triose phosphates are produced (3C)
3. Triose phosphates are oxidised to pyruvate (3C) using NAD and 2 ADP, releasing NADH and 2 ATP

Question 7

What are the products of glycolysis?

Answer 7

2 pyruvate
2 NADH
Net gain of 2 ATP

Question 8

What happens between glycolysis and the link reaction?

Answer 8

Pyruvate and NADH are actively transported from the cytoplasm and mitochondrial matrix

Question 9

Explain what happens in the Link Reaction?

Answer 9

1. Pyruvate made in glycolysis is oxidised to acetate (2C), using NAD and releasing NADH and CO2
2. Acetate combines with coenzyme A to form acetylcoenzyme A (2C)

Question 10

What are the products of the Link Reaction?

Answer 10

2 Acetyl CoA
2 CO2
2 NADH

as this happens twice

Question 11

Explain the Kreb’s Cycle

Answer 11

1. Using the acetyl CoA from the link reaction, this reacts with a 4C compound, then releases CoA to produce a 6C compound
2. a series of redox reactions:

-6C goes to 5C, uses NAD, releases NADH and CO2
-5C goes to 4C, uses NAD and ADP+Pi, releases NADH and ATP, and CO2
-4C goes to 4C, uses FAD, releases FADH
-4C goes to 4C, uses NAD, releases NADH

Question 12

What are the products of the krebs cycle?

Answer 12

(cycle happens twice)

6 NADH
2 FADH
2 ATP
4 CO2

Question 13

Explain Oxidative Phosphorylation

Answer 13

1. The electron transport chain (ETC): NADH transfes its 2 high energy electrons to the 1st protein in the ETC, so the 1st protein is now reduced. 2e- passes to the 2nd protein and so on… ( FADH donates its electrons to the 2nd protein)
2. As this happens, electrons lose energy which the proteins use to pump H+ ions from the matrix to the inter-membrane space where they build up.
3. Electrons keep moving until they have no energy, where they combine with oxygen and 2 hydrogens to make water- oxygen is described as the final electron acceptor.
4. The build up of H+ ions in the inter-membrane space is used to make ATP: diffuse down the conc gradient through the ion channel of ATP synthase to the matrix. This movement means that ADP+Pi makes ATP. = chemiosmosis.