Electron Transport Chain Flashcards
Oxidative Phosphorylation is oxygen dependent?
True
Where does the ETC and Oxygen phosphorylation take place?
Inner Mitochondial membrane
Reduced Carriers?
NADH
FADH2
ATP equivalents of NADH
3 ATP
ATP equivalents of FADH2
2 ATP
ATP equivalents of GTP?
1 ATP
How many sets of Electron transfer systemms and ATP synthas molecules in the inner mito membrane?
over 10,000!
Why do we need Mitochondria?
ATP biosynthesis Mediation of cell death by apoptosis Heat production (thermogenesis) Intermediary metabolism (e.g. TCA cycle, fatty acid metabolism) Genetics (maternal inheritance)
How many complexes are there in the ETC?
Four
Complex 1 of the ETC
Name?
what does it have?
Does it pump protons?
NADH dehydrogenase
thus oxidizes to NAD +
It pumps protons and has Fe
Complex 2 of the ETC
Name?
what does it have?
Does it pump protons?
Succinate Dehydrogenase succinate to fumarate FADH2 used Fe Heme no protons pumped
Complex 3 of the ETC
Name?
what does it have?
Does it pump protons?
cytochrome b-c1
Fe
Heme
pumps protons
Complex 4 of the ETC
Name?
what does it have?
Does it pump protons?
Cytochrome C oxidase
Cu
Heme
Complex one is blcked by?
Rotenone
Complex 3 blocked by?
Antimycin
Complex 4 blocked by?
cyanide and carbon monoxide
Iron deficiency affects ?
1,2,3
Uncoupler
hydrophobic, moves protons in both directions
Respiration (consumption of oxygen) proceeds ONLY when
ADP is present
Oxidation of substrates is coupled to the phosphorylation of?
ADP-ATP- O2 consumption
The amount of O2 consumed depends on ?
the amount of ADP added
2,4 Dintrophenol
increases oxygen consumption
oligomycin
ATP synthase inhibitor
increases O2 consumption
Chemiosmotic Theory
proton motive force is responsible for driving the synthesis of ATP
Proton gradient
Lower pH in the intermembrane
and
High pH in matrix of the mitochondria
4 Tenents of Chemiosmotic Theory
- Inner mitochondrial membrane is impermeable to protons
- Protons are pumped vectorially across inner mitochondrial membrane
- Electron transport and ATP synthesis are tightly coupled
- Presence of an ATP synthase
F1F0 - ATP synthase and energy metabolism
F0 subunit in the membrane
and
F1 as the head group
Which complex is the major source of ROS production?
Complex 3
Coenzyme
is unstable intermediates of the Q cycle can lead to superoxide formation
Protection against ROS
superoxide dismutase SOD
and catalse
The _________ transport chain comprises a series of 4 protein complexes (Complexes I-IV) together with coenzyme Q and cytochrome c that are part of the inner mitochondrial membrane. The complexes function to ______reducing equivalents from reduced coenzymes (NADH, P/O ratio=?) or substrates such as succinate/ FADH2(P/O ratio=?) to O2 with the formation of H2O and the ______________________
The mitochondrial electron transport chain comprises a series of 4 protein complexes (Complexes I-IV) together with coenzyme Q and cytochrome c that are part of the inner mitochondrial membrane. The complexes function to transfer reducing equivalents from reduced coenzymes (NADH, P/O ratio=3) or substrates such as succinate/ FADH2(P/O ratio=2) to O2 with the formation of H2O and the generation of a H+/voltage gradient across the inner mitochondrial membrane
The ________ involves various prosthetic groups including FAD, FMN, Fe/S clusters, various cytochromes (a, b and c) and Cu. Reducing equivalents are successively transferred from groups of ___________ to those of _____________ coupled with the transport of H+ across the membrane from the matrix to the intermembrane space.
The electron transport chain involves various prosthetic groups including FAD, FMN, Fe/S clusters, various cytochromes (a, b and c) and Cu. Reducing equivalents are successively transferred from groups of low redox potential (NADH) to those of higher redox potential (O2) coupled with the transport of H+ across the membrane from the matrix to the intermembrane space.
Mitochondrial function can be blocked at specific sites by the addition of inhibitors of electron transfer such as ?
Mitochondrial function can be blocked at specific sites by the addition of inhibitors of electron transfer such as:
- rotenone
- cyanide
- carbon monoxide or hydrogen sulfide (sewer gas)
In functional mitochondria, ____________ (the production of ATP, using the H+/voltage gradient across the inner mitochondrial membrane as a driving force) ________________and regulated by substrate and product availability.
In functional mitochondria, electron transport and oxidative phosphorylation (the production of ATP, using the H+/voltage gradient across the inner mitochondrial membrane as a driving force) are tightly coupled and regulated by substrate and product availability.
ATP synthesis is catalyzed by the________, the integral membrane complex that synthesizes ATP from ADP and inorganic phosphate (Pi).
ATP synthesis is catalyzed by the F1/F0 synthase, the integral membrane complex that synthesizes ATP from ADP and inorganic phosphate (Pi).
Mitochondrial diseases are?
Maternal Inheritance!
