Terminal Respiration Flashcards
<p>What do redox reaction do in respiration?</p>
<p>Pass electrons around which end up combining with oxygen</p>
<p>What is the only site of oxidative phosphorylation?</p>
<p>Mitochonria</p>
<p>What does the mitochondria allow in terms of oxidative phosphorylation?</p>
<p>The coupling of oxidation of carbon fuels to ATP synthesis</p>
<p>What structures are present in mitochondria?</p>
<p>Cristae</p>
<p>Matrix</p>
<p>Outer membrane</p>
<p>Inner membrane</p>
<p>Inter membrane space</p>
<p>What is the purpose of cristae?</p>
<p>Increases the surface area</p>
<p>What is abundant in the matrix?</p>
<p>Full of proteins</p>
<p>Where do most reactions happen in mitochondria?</p>
<p>On the inner membreane</p>
<p>Where is most NADH and FADH2found and why?</p>
<p>In the mitochondria due to citric acid cycle and B-oxidation</p>
<p>Where is some NADH and FADH2found and what needs to happen to them?</p>
<p>In the cytosol and they need to be transfered into the mitochondria</p>
<p>Which of NADH and FADH2can cross the membrane of the mitochondria?</p>
<p>NADH cannot cross the membrane, but FADH2can pass its electrons onto the electron transport chain</p>
<p>What is the passage of electrons from FADH2into the electron transport chain called?</p>
<p>Glycerol phosphate shuttle</p>
What does the glycerol phosphate shuttle look like?
<p>What happens during the glycerol phosphate shuttle?</p>
<ol> <li>NADH passes its electrons onto dihydroxyacetone phosphate which becomes glycerol-3-phosphate</li> <li>Crosses the outer membrane and passes electrons onto FAD which becomes FADH2</li> <li>FADH2enters the electron transport chain</li></ol>
<p>Which of the oxidation of FADH2and NADH generates more ATP per molecule?</p>
<p>NADH</p>
<p>What is the disadvantage of using substrates from the cytosol?</p>
<p>An energetic price is paid getting them into the mitochondria</p>
<p>What are the 4 proteins that make up the electron transport chain?</p>
<ol> <li>NADH-Q Oxidoreductase</li> <li>Succinate-Q reductase</li> <li>Q-cytochrome C oxidoreductase</li> <li>Cytochrome C oxidase</li></ol>
<p></p>
<p></p>
<p>How many of the 4 proteins of the electron transport chain push protons across?</p>
<p>3</p>
<p>What proteins of the electron transport chain push protons acorss?</p>
<p>NADH-Q oxidoreductase (1)</p>
<p>Q-cytochrome C oxidoreductase (3)</p>
<p>Cytochrome C oxidase (4)</p>
<p>What impacts the amount of energy you can yield from electron carriers?</p>
<p>Which protein of the electron transport chain they use, as succinate-Q reductase doesn't push protons through</p>
<p>What does complex 1 (NADH-Q oxidoreductase) do?</p>
<p>Oxideses NADH and passes e-onto ubiquinone to make ubiquinol (QH2)</p>
<p>Passes H+into the intermembrane space</p>
<p>What centres does complex 1 (NADH-Q reductase) use?</p>
<p>Fe-S centres</p>
<p>FMN (flavin mononuleotide)</p>
<p>What does complex 2 (Succinate-Q reductase) do?</p>
<p>OxidisesFADH2and passes e-to ubinquinone which becomes ubiquinol (QH2)</p>
<p>What centres does complex 2 (Succinate-Q reductase) utilise?</p>
<p>Fe-S centres</p>
<p>What does the haem group do in complex 2 (Succinate-Q reductase)?</p>
<p>Stops stray electrons from going somewhere else</p>
What is ubiquinone (Q) called in the mitochondria?
Q10 (10 isoprene repeats)
What are ubiquinone's other names?
Q10
Coenzyme Q10
What does complex 3 (Q-cytochrome C oxidoreductase) do?
Takes electrons from QH2 (converting it back to Q) and passes them to Cytochrome C
Pumps protons into intermembrane space
What does the oxidation of one molecule of QH2 produce?
2 molecules of reduced cytochrome C
What does complex 4 (Cytochrome C oxidase) do?
Takes electrons from cytochrome C and passes them to O2)
Pumps protons into the intermembrane space
What centres does complex 4 (Cytochrome C reductase) utilise?
Fe-Cu centres
What do electrons cause protons to do?
Work which generates a proton gradient
What are the two carriers used in the electron transport chain?
NADH
FADH2
Where does the NADH that is used in the electron transport chain come from?
Glycolysis
Citric acid cycle
B-oxidation
Where does the FADH2 that is used in the electron transport chain come from?
B-oxidation
NADH via G-3-P shuttle
How many hydrogen ions (protons) are pumped per electron?
1
What is the enzyme that uses the proton gradient to generate ATP?
ATP synthase
What is the energy stored in the proton gradient used by?
EMF (allows proton gradient to do work)
ATP synthase (acts as a molecular turbine which harnesses the energy of the gradient)
What is chemiosmosis?
Protons moving from the matrix to the outer of the inside mitochondrial membrane as e- pass through the complex of the electron transport chain
What is a proton motive force?
When protons are allowed to flow back down their concentration gradient they release energy to do work
What happens once protons eventually flow back down their concentration gradients?
ATP synthase sits on these sites which uses the energy from them passing through to convert ADP + Pi → ATP
What are the 2 parts of ATP synthase?
F0 (membrane bound protein)
F1 (protrudes into mitochondrial matrix)
What is F0?
Has 10 subunits that connect it to F1
What is F1?
Produces ATP from proton motive force energy connected by F0
What is the process of ATP synthase performing its function?
- ADP + Pi enter beta sub unit
- Rotation of F0 cylander and gamma shaft causes a confirmational change in the beta subunit of F1
- Catalyses ADP + Pi → ATP
What is most of the energy used by ATP synthase required for?
Releasing the formed ATP
How many H+ leave as one goes in?
1
How does the sequential conformational change of the beta subunit of F1 work?
B1 binds ADP + Pi (ready to react)
B2 binds ATP (ready to be released)
B3 doesn't bind ATP (empty)
When does F0 rotate?
Once every 2 protons enter the space
How much ATP does 3 H+ produce?
1 molecule
Why does NADH pump more protons than FADH2?
It enters the first complex whereas FADH2 enters the second
Stoichiochemically, how much ATP does NADH and FADH2 produce?
NADH generates 2.5 molecules of ATP per molecule
FADH2 generates 1.5 molecules of ATP per molecule
What is the total yield of ATP per molecule of glucose?
30 or 32 molecules of ATP, most from electron carriers
What happens if the inner mitochondrial membrane becomes permeable to H+?
H+ concentration gradient cannot be generated
Electron transport chain reduces O2 to H20 still, but no ATP is generated
Energy is released as heat instead
What is it called when the inner mitochondrial becomes permeable to H+?
Uncoupling
When is uncoupling intentional and why?
In brown fat to generate heat
