27 - Electron Transport and Oxidative Phosphorylation Flashcards
NADH and FADH2 are produced by what 3 processes?
Glycolysis
Fatty acid oxidation
TCA cycle
What is the final acceptor of the electron transport chain?
O2
What happens in oxidative phosphorylation?
The electrons from NADH and FADH2 (2 each) reduce the O2 (final acceptor in ETC) to H20 and drive the formation of ATP the movement of protons down their concentration gradient, driving the formation of ATP from ADP with the enzyme ATP synthase
The inner membrane of the mitochondrion is protein-rich. It is impermeable to what and permeable to what (in general terms)?
Impermeable
- Metabolites (eg. ATP, ADP)
- Ions (eg. H+, phosphate)
Permeable
- O2, H2O and CO2
Where does electron transport and oxidative phosphorylation take place in the mitochondrion? Where do protons accumulate to build the proton gradient?
The inner membrane
Protons accumulate in the intermembrane space
What do:
- FMN (flavin mononucleotide)
- Coenzyme Q/ubiquinone (CoQ)
- Iron-sulfur cluster (FeS)
- Heme α
Do?
These molecules transport electrons
How are electron carriers in the ETC arranged in the inner membrane?
In order of increasing electron affinity
How many components of the ETC are there? What does each function as?
There are 4 complexes and one cytochrome C, each acts as an oxidoreductase.
What is the path electrons take through the electron transport chain? (Just list complex numbers or symbols)
NADH - I - UQ - III - Cyt C - IV -O2
FADH2 - II - UQ - III - Cyt C - IV - O2
List the complexes (5) of the ETC and their prosthetic groups
Complex I (NADH dehydrogenase) - FMN, FeS
Complex II (succinate dehydrogenase) - FAD, FeS
Complex III (Cytochrome bc1 complex) - Hemes, FeS
Cytochrome C
- Heme
Complex IV (cytochrome oxidase) - Heme, Fe, Cu
What does complex I (NADH dehydrogenase) of the ETC do?
Catalyzes transfer of electrons from NADH to ubiquinone (UQ)
Electron movement is accompanied by a net movement of protons from the matrix to intermembrane space
What does Ubiquinone (coenzyme Q) do? What is it?
It is a lipid-soluble mobile electron carrier that can transfer electrons one at a time.
What is the nutritional supplement known as CoSQ10 (Q10)?
The form of ubiquinone with 10 isoprenoid units
What does complex II (succinate dehydrogenase complex) do in ETC?
Transfers electrons from succinate via FAD to UQ
It is also the path of electrons from succinate, glycerol-3-phosphate and fatty acids to UQ
Where can UQ get electrons from in the ETC?
- Complexes I and II
- Fatty Acyl-CoA oxidation
- Glycerol-3-phosphate dehydrogenases