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17 Cards in this Set
- Front
- Back
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What two components give rise to the gradient across the mitochonrial inner membrane
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1. Chemical (because of differnece in pH)
2. Membrane potential (because protons are charged) |
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How many ATP are formed for each NADH
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2.5
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How many ATP are made for each FADH2
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1.5
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What is the P/O ratio
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measure of phosphorylation efficiency, refers to the number of high energy bonds formed per 1/2O2 reduced to water. NADH=2.5, FADH=1.5
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What is the respiratory control index
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-measure of how tightly mitochondrial respiration (use of O2) is coupled to ATP synthesis
-high control= perfecly coupled -low control= uncoupled |
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What is the pH and membrane potential across the inner membrane
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pH=up to 1.4 units
potential= 0.14V gives rise to porton motive force=membrane potential and chemical gradient |
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How is the P/O ratio for NADH calculated
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each NADH leads to 10 protons being pumped out, each ATP needs 4 protons to be made, 10/4=2.5
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How is the P/O ratio for FADH2 calculated
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each FADH2 leads to 6 protons being pumped out, each ATP needs 4 protons to be made 6/4=1.5
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How is the RCI determined
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The RCI is the slope of the oxygen consumption curve of a working cell over a resting cell (working~totally couped, resting=uncoupled, working is the steeper slope)
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What is the affect of DNP on oxphos
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DNP is an uncoupler. It dissipates the electrochemical gradient by shuttling protons back into the matrix.
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How does ATP synthase work
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-Embeded in mitochondrial inner membrane
-Fo subunit= channel, F1= axel -Protons flow through the channel and remove H2O from ADP+Pi to for ATP, it's literally squished together |
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Describe how physiological uncoupling occurs in BAT
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BAT has the protein UCP1 (thermogenin) which allows protons to reenter the matix without making ATP. The energy of the proton gradient is instead released as heat (lowers the RCI). This results in non-shivering thermogensis which is important in infants
Note this is powered byfree fatty acids which also activate UCP1 |
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How many ATP per glucose are obtain from complete oxidation via the glycerol phosphate shuttle? Malate asparate?
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Glycerol phosphate=30
malate asparate=32 |
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Why are there 2 less ATP/glucose made via glycerol-phosphate shuttle than the malate-aspartate shuttle
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In the glycerol phosphate shuttle, NADH is converted to FADH2 which only yield 1.5 ATP, there are two of these events per glucose so 3 ATP are made.
In the malate-aspartate shuttle, the NADH is converted back to NADH. 2.5 ATP/NADH are made and this happens twice/glucose so 5 ATP are made. THis accounts for the 2 ATP difference |
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Account for each of the 30 ATPs made in oxidative phosphorylation via the glycerol-phosphate shuttle
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Glycolysis=+2 (-2, +4)
TCA=+2 (from GTP) OX phos -2 NADH from glycolysis X1.5 (converted FADH2 in shuttle)=3 -PDH=2pyruvate=> NADHX2.5=5 -2 FADH2 from TCA x1.5= 3 -6 NADH from TCA x2.5=15 total=30 |
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Account for each of the 32 ATP's made for oxidative phospohrlation of 1 glucose molecule using the malate-aspartate shuttle
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Glycolysis=+2 (-2, +4)
TCA=+2 (from GTP) OX phos -2 NADH x2.5=5 -PDH=2pyruvate=> NADHX2.5=5 -2 FADH2 from TCA x1.5= 3 -6 NADH from TCA x2.5=15 total=32 |
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remember that you need both ADP and Pi to keep ATP synthesis and the ETC going
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seriously, remember that
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