Oxidative Phosphorylation: Binding Change Mechaniesm Flashcards
Which of F1’s 3 alpha-beta catlytic protomers is catalytically active? Which two are inactive?
Active= T state (binds substrate and products tightly). Inactive = L state (binds substrate loosely) and O state (does not bind substrate).
What is the free energy released by proton translocation used to do?
Interonvert the states of F1
Which state must F1 be in for the phosphoanhydride bond to form?
T state
Which state must F1 be in for ATP to be released?
O state
Which state of F1 do ADP and Pi bind to?
L state
What induces a conformation change of F1? What change is induced?
Free energy from dissipation of proton gradient; Converts L to T state, catalyzing ATP synthesis. Also causes conformation changes in two other protomers that convert ATP containing T site to O site and O site to L site.
True or false: ATP is synthesized at a T site on 1 subunit while ATP dissociates from an O site on another subunit.
True
True or false: Synthesis of ATP on inner-mitochondrial membrane is a substate level phosphorylation
True
Who proposed the Binding Change Mechanism theory?
Paul Boyer
What is the name for the mechanism by which ATP synthase synthesizes ATP?
Binding Change Mechanism
True or false: Any beta subunit can perform any of the three sequential steps in the process of ATP synthesis by changing conformation.
True
What are the three steps in the process of ATP synthesis?
1) Trapping ADP and Pi (L state)
2) ATP synthesis (T state)
3) Release of ATP (O state)
What drives the interconversion of the three states of the beta units of F1 of ATP synthase?
Rotation of the gamma subunit (powered by free energy from the proton motive force).
In which F1 state of ATP synthase is a phosphoanhydride bond formed between ADP and Pi?
T state
In which F1 state of ATP synthase is a ATP released?
O state
