7 - AEROBIC RESPIRATION (STAGE 4)

Question 1

What is the fourth stage of aerobic respiration?

Answer 1

Oxidative phosphorylation

Question 2

Explain this stage

Answer 2

Oxidative phosphorylation is the process in which ATP is synthesised via chemiosmosis in the electron transport chain in mitochondria, this process generates the majority of ATP in aerobic respiration

Question 3

1st step

Answer 3

Hydrogen atoms are released from reduced NAD and reduced FAD as they’re oxidised to NAD and FAD.

Question 4

2nd step

Answer 4

The H atoms split into protons and electrons

Question 5

3rd step

Answer 5

The electrons move down the electron transport chain (made up of electron carriers), losing energy at each carrier

Question 6

4th step

Answer 6

This energy is used by the electron carriers to pump protons from the mitochondrial matrix into the inter membrane space (space between the inner and outer mitochondrial membranes)

Question 7

5th step

Answer 7

The concentration of protons is now higher in the inter-membrane space than in the mitochondrial matrix - forming an electrochemical gradient ( a concentration gradient of ions)

Question 8

6th step

Answer 8

Protons move down the electrochemical gradient, back into the mitochondrial matrix, via the enzyme ATP synthase. This movement drives the synthesis of ATP from ADP and inorganic phosphate

Question 9

What is the movement of H+ ions across a membrane which generates ATP called?

Answer 9

chemiosmosis

Question 10

7th step

Answer 10

In the mitochondrial matrix, at the end of the transport chain, the protons, electrons and O2 from the blood combine to form water.

Question 11

What is oxygen said to be?

Answer 11

The final electron acceptor.