Oxidative Phosphorylation Flashcards
(34 cards)
<p>What are the two stages in oxidative phosphorylation?</p>
<p>- Electron transport
| - ATP Synthesis</p>
<p>From one glucose molecule, the reactions of... - glycolysis - pyruvate dehydrogenase complex - TCA cycle produce how many NADH + H and FADH2?</p>
<p>- 10 NADH + 10H+
| - 2 FADH2</p>
<p>Each one of NADH + H+ and FADH2 carries how many high energy electrons?</p>
<p>2</p>
<p>Steps of Oxidative Phosphorylation</p>
<p>- Electrons from NADH and FADH2 are used to reduce O2 to H2O
- Their energy is used to pump protons (H+) from the mitochondrial matrix to the intermembrane space
- Protons flow back across the membrane, following their concentration gradient
- Energy of proton flow is used to phosphorylate ADP to ATP</p>
<p>PH decreases in the \_\_\_\_\_\_\_\_\_\_ and increases in the \_\_\_\_\_\_\_\_\_\_</p>
<p>- membrane space
| - matrix</p>
<p>NADH cannot cross the...</p>
<p>inner mitochondrial membrane</p>
<p>NADH cannot be re-oxidised to NAD+ directly using ....</p>
<p>the electron transport chain</p>
<p>What overcomes NADH being unable to be re-oxidised using the electron transport chain?</p>
<p>The glycerol-3-phosphate and malate-aspartate shuttle</p>
<p>During glycolysis, how many NADH are formed in the cytoplasm?</p>
<p>2 NADH</p>
<p>How is the phosphoryl transfer potential measured?</p>
<p>measured by the free energy change, (delta G0) for the hydrolysis of ATP</p>
<p>How is the electron transfer potential measured?</p>
<p>measured by the redox potential (or reduction potential), E0 of a compound</p>
<p>What is the standard redox potential E0 of a reduced substance?</p>
<p>A measure of how readily the substance donates an electron</p>
<p>What does a negative E0 mean?</p>
<p>the reduced form of the substance has a lower affinity for electrons than H2</p>
<p>What does a positive E0 mean?</p>
<p>the reduced form of the substance has a higher affinity for electrons than H2</p>
<p>Standard free energy change is proportional to...</p>
<p>the change in standard redox potential and the number of electrons transferred</p>
<p>Oxidative phosphorylation is the coupling of...</p>
<p>respiration to ATP synthesis</p>
<p>Electron transport chain occurs when electrons flow from</p>
<p>NADH and FADH2 to O2</p>
<p>Electron transport - respiratory chain</p>
<p>- Electrons from NADH enter at complex I, electrons from FADH2 enter at complex II (TCA cycle)
- Electrons are handed down from higher to lower redox potentials
- Transferred onto O2 to form H2O</p>
<p>Transfer of electrons through the respiratory chain is coupled to what?</p>
<p>coupled to H+ transport from mitochondrial matrix to intermembrane space</p>
<p>Electron transport and ATP synthesis are catalysed by what?</p>
<p>Catalysed by separate proton pumps</p>
<p>What is a cytochrome?</p>
<p>Proteins which contain a haem group as a functional co-factor</p>
<p>Haem contains an Fe(II) ion which can do what?</p>
<p>Take up and release electrons</p>
<p>Transfer of electrons through the respiratory chain is coupled to...</p>
<p>transport of H+ from the mitochondrial matrix to the intermembrane space</p>
<p>How many out of the four respiratory complexes pump H+?</p>
<p>3/4</p>
Electrochemical Gradient Mechanism
- more protons in the intermembrane space than in the matrix - forms an electrical field with the matrix side more negative - protons want to flow back into the matrix - flow back into the matric is coupled to ATP synthesis
The respiratory chain pumps protons into where?
The intermembrane space
After being pumped into the intermembrane space by the repiratoy chain, protns flow back through...
ATP synthase (two seperate proton pump systems)
