ATP Synthesis: Putting It All Together Flashcards
What happens to some of the energy during glycolysis and the TCA cycle?
it is transferred to coenzymes such as NADH and FADH
What does the F1 complex consist of?
a static component that consists of beta subunit plus a catalytic ring formed by a hexagon of alternating alpha and beta subunits
a mobile component that consists of sigma and gamma subunits which form the central stalk that is firmly attached to the c10 ring of F0
What does the F0 complex consist of?
static component consists of one a and two b subunits, the a subunit forms the proton channel and is immobilized in the membrane
the mobile component consists of a ring of 10 c subunits, only one c subunit can form an ionic bond with the a subunit at a time
Define proton translocator.
a channel through which protons flow across the mitochondrial inner membrane
What is the binding change model?
Who discovered it?
Paul Boyer
each of the beta subunits of the F1 complex is in a different conformation at any instant
O (open), L (loose) and T (tight)
rotation was thought to be driven by the flow of protons though F0, now known that it is the gamma subunit that actually rotates
Describe the steps of the Binding change model, there are 3 with a and bs
1a. the beta subunit in the O conformation shifts to the L conformation whent he flow of protons through the F0 causes a 120 degree rotation of the gamma subunit
1b. ATP is synthesized by beta
2a. The gamma subunit rotates another 120 degrees, inducint beta 1 to shift to the T conformation
2b. the beta 1 subunit has and increased affinity for ADP and Pi allowing sponataneous formation of ATP
3a. the gamma subunit rotates another 120 degrees inducing beta 1 to shift to the O conformation, releasing ATP
Following ATP generation by the beta, until the cycle is complete
Why does the binding change model use no energy input?
the catalytic site of a beta subunit is sch that the cahrge repulsion is minimized, favoring ATP formation with a change in energy close to zero
Although the model does not use energy, it is still needed.. where does the energy needed occur?
the needed input of energy occurs elsewhere in the cycle, energy comes from the proton gradient generated by electron transport and transmitted through rotation of the gamma subunit
What is the chemiosmotic model?
complex 1, 3 and 4 of the ETS pump protons outward across the inner membrane of the mitochonrdion, where they accumulate in the intracristal space
the resulting electrochemical gradient then drives aTP generation by means of the F0F1 complexes associated witht the inner membrane
What is the complete ATP yield through one cycle of aeorbic respiration?
38 ATP per 1 glucose
