BIOC192 Lecture 33 - Oxidative Phosphorylation Flashcards
what are the 2 energetic gradients that result from the proton gradient across the inner mitochondrial membrane?
1) a chemical gradient
2) an electrical gradient
what is the chemical gradient/pH gradient a result of?
result of different H+ concentrations on either side of the membrane
what is the electrical gradient a result of?
result of the charge difference across the membrane (positive in the inter membrane space, negative in the matrix)
what is the electrochemical gradient known as?
known as the proton motive force
what is bacteriorhodopsin?
a light inducible proton pump
does ATP synthase make ATP when the light was switched on?
yes
does ATP synthase make ATP when the light was switched off?
no
what is DNP molecule ?
an uncoupler
what is the function of DNP molecule?
shuttles H+ from the inter-membrane space to the matrix, thus dissipating the proton gradient
what 2 things happen in the presence of DNP?
1) ETC functions
2) no ATP is made
what happens to the energy stored in the proton gradient?
converts to heat
what is average number of ATP-synthases per cell?
40,000
what is immobilised ATP-synthase linked to?
linked to fluorescent actin
what part of the F1Fo-ATP synthase turns?
rotor subunits
where is F1 located?
in the matrix
where is the Fo located?
in the membrane
what part of the F1Fo-ATP synthase does not turn?
stator subunits
what drives rotor movement?
proton flow
what does rotor movement cause?
causes a conformational changes in the stator that drives ATP synthesis
what are the 3 conformational changes?
1) O=open
2) T=tight
3) L=loose
what does the open conformational change lead to?
leads to release/binding
what does the tight conformational change lead to?
leads to ATP formation
what does the loose conformational change lead to?
holds ADP and Pi in preparation fro catalysis
how many protons does it take to make 1 ATP?
4 protons
how many ATP are made from NADH (10 protons)?
2.5 ATP made
how many ATP are made from FADH2 (6 protons)?
1.5 ATP made