Lecture 23(FIX) Flashcards
(17 cards)
What is oxidative phosphorylation?
It is the coupling of energy release during electron transport to ATP synthesis. Converting the free energy of the proton gradient for ATP synthesis.
What does the chemiosmotic theory state?
The free energy from electron transport drives an active transport system, which pumps protons out of the mitochondrial matrix into the intermembrane space.
Where is ATP synthesized? What is it known as?
It is synthesized in complex V and is known as ATP synthase
What makes up ATP synthase?
Two large complexes, F1 and F0.
What is the F1 complex?
he F1 knob-like structure contains three αβ dimers, making up the central stalk are γ, δ, and ε subunits (also part of complex F1).
What is the central stalk?
It is the rotor of the ATP synthase
What is the F0 complex?
The F0 complex is located within the inner membrane of the mitochondria. The F0 subunits (a, b, d, f6, c-ring and OSCP) makeup the “stator”, a structure that prevents the rotation of the three αβ dimers of F1.
What are the B conformational subunit?
Loose(L), Tight(T), and Open(O). These are controlled by gamma.
What does loose(L) do?
binds ADP and inorganic phosphate in a loose conformation
What does tight(T) do?
catalyzes the formation of ATP from bound ADP and inorganic phosphate
What does open (O) do?
ATP can now be released and a new ADP and inorganic phosphate can enter the enzyme
How does the proton-motive force drive rotation of the F0 assembly?
An aspartic acid residue in the c subunit and the two half channels in the a subunit key
What is the nature of the delta chain?
It has a half channel where protons feed in and go out. They have hydrophilic character
What is true about the aspartic acid?
It is positioned in a way where it comes into contact with two different environments. It is also ionizable. In hydropbhobic= pronated, in hydrophillic=deprotaned
