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27 Cards in this Set

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2 reasons why ETC creates energy for ATP synthesis:
1. Establishes voltage gradient
2. Establishes proton gradient
What is the P/O ratio?
A measure of phosphorylation efficiency; the # of phosphate bonds made per 1/2O2 -> H2O
What is the P/O upper limit of:
-NADH
-FADH2
NADH = 2.5

FADH2= 1.5
What is the overall efficiency of converting NADH E into ATP?
35%
What is the chemiosmotic hypothesis?
That ETC creates a H+ gradient across the inner mito membrane.
What is the pH of the intermembrane space? Is this space pos or neg charged?
1.4 units lower (more H+) than matrix; Pos charged w/ ref to matrix.
What is the membrane potential established by PMF?
.14 V
What makes up the Proton Motive Force? (2 things)
-Membrane potential contribution
-Chemical gradient contribution
What is Respiratory control index (RCI)?
slope of [O2]vs time in State 3 vs State 4 mitochondria
What info does RCI give?
A measure of how tightly couple O2 consumption and ATP formation are.
What state has a high RCI?
Healthy mitochondria - protons don't leak back into the matrix and ETC pumps expected # of H+
What does cyanide do?
reversibly inhibits complex 4
What inhibits ATP synthase?
Oligomycin
What uncouples the ETC from ATP synthase?
DNP - dinitrophenol
How does DNP work?
It allows H+ to flow back into the mitochondria without driving ATP synthesis
What are 3 other uncouplers?
-Aspirin (proton shuttle)
-Valinomycin/gramicidin - replace H+ w/ K+ or Na+
How does proton flow affect ATP Synthase?
It causes conformation changes that remove H2O from ADP+Pi to form ATP
What component of ATP synthase
-is in the matrix?
-is in the membrane?
Fo = in the membrane

F1 = in the matrix
How many protons are required for a conformational change?
4
When is uncoupling of PMF and ATP synthase good?
When the energy is required for thermogenesis instead of ATP
What tissue accomplishes this?
Brown adipose tissue
What is unique about the mitochondria in BAT?
it contains an inner membrane ion transporter - UCP-1
What is UCP1?
Uncoupling protein 1 aka Thermogenin
What does UCP1 do?
Allows protons to flow back into matrix and makes HEAT instead of ATP.
What is the RCI in BAT mitochondria?
LOW
What stimulates BAT thermogenesis?
Obesity and overeating
What is genetic obesity associated with?
reduced BAT and lower thermogenesis.