Aerobic Respiration Stage 4 - Oxidative phosphorylation and the electron transport chain

What is chemiosmosis? (3)

The diffusion of protons across the inner mitochondrial membrane, down an electrochemical gradient, through ATP synthase

Where does the electron transport chain occur?

on the cristae of the inner mitochondrial membrane

What is stage 1 of the electron transport chain?

oxidation of reduced NAD and reduced FAD

Outline stage 1 of the electron transport chain as the oxidation of reduced NAD and reduced FAD (reduced NAD) (3)

NADH is oxidised and releases a hydrogen atom into the mitochondrial matrix, the hydrogen atom splits into one electron and one proton, the electron is donated to the first cytochrome in the electron transport chain

Outline stage 1 of the electron transport chain as the oxidation of reduced NAD and reduced FAD (reduced FAD)

reduced FAD is oxidised and releases the 2 hydrogen atoms into the mitochondrial matrix, the 2 electrons are donated to the second cytochrome in the electron transport chain

What happens to the NAD and FAD after stage 1?

FAD and NAD return to the previous stages of respiration

What is stage 2 of the electron transport chain?

energy release

Outline stage 2 of the electron transport chain as the energy release from electron movement (2)

as the electron moves through the electron transport chain energy is released, this provides energy for the active transport of protons to move from the mitochondrial matrix to the inter-membrane space via proton pumps

What is stage 3 of the electron transport chain?

electrochemical gradient established

Outline stage 3 of the electron transport chain as the electrochemical gradient established (4)

protons accumulate in the inter-membrane space, so there is a greater positive charge in the inter-membrane space than the mitochondrial matrix, an electrochemical gradient is formed and maintained by proton pumps, protons move back down their electrochemical gradient through ATP synthase by passive diffusion from the inter-membrane space to the mitochondrial matrix

What is stage 4 of the electron transport chain?

energy release from proton movement

Outline stage 4 of the electron transport chain as the energy release from proton movement (2)

flow of protons through the stalked particle with ATP synthase releases energy, this energy catalyses the reaction between ADP and inorganic phosphate forming ATP

What is stage 5 of the electron transport chain?

oxygen as the final electron acceptor

Outline stage 5 of the electron transport chain as oxygen as the final electron acceptor (3)

protons and electrons in the mitochondrial matrix react with oxygen to produce water, oxygen is reduced as it gains electrons, the formation of water maintains steep proton gradient

How does cyanide cause cells to die? (5)

cyanide is a non-competitive inhibitor of the final electron carrier in the electron transport chain, preventing the formation of water from protons and electrons and oxygen in the mitochondrial matrix, so the proton gradient is not maintained, therefore inhibiting the formation of ATP, causing the cell to die

What are the reactants in the electron transport chain? (5)

reduced NAD, reduced FAD, oxygen, ADP, inorganic phosphate

What are the products from the electron transport chain? (4)

NAD, FAD, water, ATP