chemiosmosis

what is chemiosmosis?

• movement of protons down a proton gradient through ATP synthase to generate ATP

what is ATP synthase (chemiosmosis)?

• it is associated with a protein channel in the mitochondrial membrane

• when protons diffuse through the membrane through a protein channel associated with ATP synthase, ATP is generated

is chemiosmosis a theory or proven?

• theory

• there is evidence to back up the theory

what is the chemiosmosis experiment?

• They tested the pH of the mitochondrial matrix and found that it was higher than the pH of the intermembranal space

• Matrix pH = higher so fewer H+ ions

• Intermembranal space pH = pH lower so more H+ ions

• This shows that there were lots of H+ ions in the intermembranal space

• It also shows fewer H+ ions in the matrix

• This shows a H+ ion gradient between the matrix and the intermembranal space of the mitochondria

what are the total number of reduced NAD and FAD molecules produced in respiration and how many ATP molecules made from these?

reduced NAD: 10, ATP = 30

reduced FAD: 2, ATP = 4

Total ATP = 34

what is the theoretical yield of ATP from respiration?

30-38

why is the theoretical maximum yield of ATP never reached (respiration)?

• Pyruvate has to be actively transported from the cytoplasm into the mitochondrial matrix

• Proton leakage across the inner mitochondrial membrane, therefore fewer protons pass through the protein channel associated with ATP synthase