oxidative phosphorylation

what stage of aerobic respiration is this?

• the final stage

where does oxidative phosphorylation take place?

• the inner mitochondrial membrane

what is the process of oxidative phosphorylation?

• where energy carried by electrons, from reduced coenzymes (reduced NAD and reduced FAD), is used to make ATP

  • (the whole point of the previous stages is to make reduced NAD and reduced FAD for the final stage)

what 2 steps does oxidative phosphorylation require?

• the electron transport chain

• chemiosmosis

electron transport chain?

• NADH and FADH2 (from the krebs cycle are oxidised by the first electron carrier in the inner mitochondrial membrane

• this initiates oxidative phosphorylation because NADH and FADH2 release 2 protons and 2 electrons each

• the electrons are then transferred along the electron transport chain

protein gradient?

• as the electrons move down the electron transport chain, they lose energy

• this energy pumps the protons from NADH and FADH2 into the intermembrane space

• this creates a protein gradient

chemiosmosis?

• the protons diffuse down the concentration gradient through the ATP synthase enzyme

• as protons flow through the ATP synthase, energy is released

• this energy converts ADP and inorganic phosphate to ATP

the final electron acceptor?

• after the electrons have reached the end of the electron transport chain and protons have flowed through the ATP synthase enzyme, they combine with oxygen to form water

  • oxygen is called the final electron acceptor for this reason

what can ATP production be affected by?

• mitochondrial diseases

how do mitochondrial diseases affect the functioning of mitochondria?

• they can affect how proteins involved in oxidative phosphorylation or the krebs cycle function, reducing ATP production

• this may cause anaerobic respiration to increase, to try make up some of the ATP shortage

• this results in lots of lactate production, causing muscle fatigue and tiredness

• some lactate will also diffuse into the bloodstream, leading to high lactate concentrations in the blood

how much ATP can be made from one glucose molecule?

• 32