Oxidative phosphorylation Flashcards
What is the definition of Redox?
Redox = Oxidation + Reduction
Oxidation is the loss of electrons, and reduction is the gain of electrons.
What does oxidation refer to in a redox reaction?
Loss of electrons
Oxidation is part of the redox process where electrons are lost.
What does reduction refer to in a redox reaction?
Gain of electrons
Reduction occurs alongside oxidation in redox reactions.
What is Redox Potential (E0)?
The tendency of chemical species to acquire electrons and therefore be reduced
Measured in Volts (V) or millivolts (mV).
What is the standard reference for redox potential?
Hydrogen, E = 0
Any substance more electronegative than hydrogen has a positive redox potential.
Where does oxidative phosphorylation occur in eukaryotes?
In mitochondria
Oxidative phosphorylation is linked with the TCA cycle and fatty acid oxidation.
What is the main function of the Electron Transport Chain (ETC)?
Production of ATP
The ETC also involves the transfer of electrons.
What complexes are part of the Electron Transport Chain?
Complexes I, II, III, and IV
These complexes are located in the inner mitochondrial membrane.
What is the role of Coenzyme Q (CoQ) in the ETC?
Acts as a collection point and electron carrier
CoQ can diffuse through the inner mitochondrial membrane and receives electrons from Complexes I and II.
What is the function of Complex III in the ETC?
Passes electrons gathered by CoQ to cytochromes
Complex III contains cytochrome c1, cytochrome b562, cytochrome b566, and an iron-sulfur protein.
What is the final step of the electron flow in Complex IV?
Reduction of oxygen to water
Requires 4 electrons from cytochrome c.
How many ATP molecules are generated for each NADH that enters the ETC?
2.5 ATP
FADH2 generates 1.5 ATP molecules as it enters the ETC at a later stage.
What is the structure of F0F1 ATP Synthase?
F0: Mitochondria; F1: Matrix
F1 contains 12 identical c subunits and 3 αβ subunits.
What are the three conformations of the ATP Synthase catalytic sites?
Open, Loose, Tight
Each conformation has a specific role in ATP synthesis.
What is the function of uncouplers in ATP synthesis?
Delink energy proton gradient from ATP synthesis
Example: Thermogenin in brown fat generates heat instead of ATP.
What is the byproduct of the Electron Transport Chain?
Water (H2O)
The process also requires the presence of O2.
What are the energy-rich molecules involved in oxidative phosphorylation?
NADH and FADH2
These molecules are oxidized in the process to produce ATP.
