1. Electron transport chain and chemiosmosis

2. Recap
Glycolysis Link Reaction Krebs Cycle Activity – In pairs, without looking at your notes outline the Krebs cycle on the white boards.

3. Electron transport chain
Most ATP is made from glucose catabolism
Oxygen is needed
Occurs on the inner membrane on mitochondrion and on the membranes of the cristae.
Involves electron carriers - cytochromes

5. Electron transport chain
The Electron Transport Chain
The hydrogen carriers (NADH + H+ and FADH2) provide electrons to the electron transport chain on the inner mitochondrial membrane
As the electrons cycle through the chain they lose energy, which is used to translocate H+ ions to the intermembrane space (creating a gradient)
The hydrogen ions return to the matrix through the transmembrane enzyme ATP synthase, producing multiple ATP molecules (via chemiosmosis)
Oxygen acts as a final electron acceptor for the electron transport chain, allowing further electrons to enter the chain
Oxygen combines the electrons with H+ ions to form water molecules
The electron transport chain produces the majority of the ATP molecules produced via aerobic respiration (~32 out of 36 ATP molecules)

6. Chemiosmosis

7. Homework
Complete notes on oxidative phosphorylation and the electron transport chain
Use powerpoint on biologyb.com to support
Complete essay question
Dues Thursday 16th March

8. Chemiosmosis
Oxidative phosphorylation describes the production of ATP from oxidised hydrogen carriers (as opposed to substrate level phosphorylation)
When electrons are donated to the electron transport chain, they lose energy as they are passed between successive carrier molecules
This energy is used to translocate H+ ions from the matrix to the intermembrane space against the concentration gradient
The build up of H+ ions creates an electrochemical gradient, or proton motive force (PMF)
The protons return to the matrix via a transmembrane enzyme called ATP synthase
As they return they release energy which is used to produce ATP (from ADP and Pi)
This process is called chemiosmosis and occurs in the cristae
The H+ ions and electrons are combined with oxygen to form water, allowing the process to be repeated anew

9. Electron Transport Chain (oxidative phosphorylation)
Glycolysis
Key
Cytoplasm
Mitochondrial matrix
Inner membrane of mitochondria
Pyruvate
Acetyl CoA
CO2
H2O O2
ATP
Reduced NAD
Reduced FAD
Link Reaction
Krebs Cycle
Electron Transport Chain (oxidative phosphorylation)

10. Electron Transport Chain (oxidative phosphorylation)
Glycolysis
Key
Cytoplasm
Mitochondrial matrix
Inner membrane of mitochondria
Pyruvate
Acetyl CoA
CO2
H2O O2
ATP
Reduced NAD
Reduced FAD
Link Reaction
Krebs Cycle
Colour code your diagram to show what happens where, and what happens to all the stuff produced in each stage of respiration
Electron Transport Chain (oxidative phosphorylation)

11. Electron Transport Chain (oxidative phosphorylation)
Glycolysis
Key
Cytoplasm
Mitochondrial matrix
Inner membrane of mitochondria
Pyruvate
Acetyl CoA
CO2
H2O O2
ATP
Reduced NAD
Reduced FAD
Link Reaction
Krebs Cycle
Electron Transport Chain (oxidative phosphorylation)

12. Electron Transport Chain (oxidative phosphorylation)
Glycolysis
Key
Cytoplasm
Mitochondrial matrix
Inner membrane of mitochondria
Pyruvate
Acetyl CoA
CO2
H2O O2
ATP
Reduced NAD
Reduced FAD
Link Reaction
Krebs Cycle
Electron Transport Chain (oxidative phosphorylation)

13. Respiration Remix