Electron Transport Chain Flashcards
TCA Cycle and cancer:
The loss of ____ _____ prevents the repair of double stranded DNA breaks, and the cell accumulates mutations. ____ is the substrate to FH. ____ accumulates and acts as a oncometabolite by blocking HIF Prolyl hydroxylase and other alpha-ketoglutarate dependent dioxygenases
Fumarate hydratase (FH)
Fumarate
Fumarate
The electron transport chain conveys electrons from ___ and ____ to molecular oxygen to make water. The energy from this electron transfer is used to create a ___ ____ across the inner mitochondrial membrane. _____ ____ uses the energy of this proton gradient to add inorganic phosphate to ____, creating ATP.
NADH and FAD2H
Proton gradient
ATP synthase
ADP
ATP synthase allows protons to come back into the ___ ____ powering ATP synthesis
Mitochondrial matrix
When the electron chain reduces NADH, the electrons are Carried from complex I through _____ __ to complex III, then through ____ __ to complex IV.
Coenzyme Q
cytochrome C
Complex ____ reduces molecular oxygen to water
IV
When NADH is used, ____ protons are pumped from the matrix to the intermembrane space, creating the ____ ___
10
Proton gradient
When FAD2H is used, complex ___ performs the oxidation, not Complex I for NADH. Other than that difference, the path is the same
II
When FAD2H is used, ___ protons are pumped across the inner mitochondrial membrane
6
Complex II uses ____ ____ to oxidize FAD2H
Succinate dehydrogenase
Complex I uses ___ ___ to oxidize NADH to NAD+
NADH dehydrogenase
Acyl CoA dehydrogenase in Fatty acid beta-oxidation and glycerol 3 phosphate dehydrogenase can also use ____ and transfer electrons to ____ __
FAD
coenzyme Q
Complex I pumps ___ protons to the intermembrane space
4
Coenzyme Q is lipid soluble and exists in the inner mitochondrial membrane. It can except one electron to form ____ which is its half reduced form, and is the main source of oxidative stress.! it’s fully reduced form is ____.
Semiquinone
Dihydroquinol
Reduced Coenzyme Q (QH2) drops ___ protons off in the intermembrane space as it is oxidized by _____. Then electrons pass directly to ____ through iron-sulfur protein subunits
2
Complex III
Cytochrome C
The oxidation of NADH and the reduction of O2 through complexes I, III, and IV pump ___ protons to the intermembrane space
10
Complex IV uses ____ ___ to oxidize 2 protons and 1/2 O2 to form water
Cytochrome oxidase
The 6th step of TCA cycle using ___ ___ to oxidize Succinate to Fumarate is part of the ____ ___ ___ in Complex II, involved in creating the proton gradient
Succinate dehydrogenase
Electron transport chain
Because complex II (Succinate dehydrogenase) does not span the ___ ___ ___, no protons are pumped into the intermembrane space when it transfers electrons to Coenzyme Q
Inner mitochondrial membrane
Incomplete reduction of oxygen forms ___ ___. Semiquinone interacts with O2, transferring a single electron and forming _____.
Free radicals
Superoxide (O2-)
The ___ ___ is a form of oxidative stress
Hydroxyl radical
Protons flow through 12 ___ ____ in the F0 portion of ATP synthase. This rotates the ___ portion which catalyzes ___ synthesis
C subunits
F1
ATP
Summary of drug effects on electron transport chain:
_____ is a proton channel called thermogenin. It is activated by norepinephrine which allows fat to be utilized for heat, independently of ATP consumption
UCP1
Activation of MPTP can lead to ____ or ____ (non programmed cell death).
Apoptosis
Necrosis
_____ is released through the MPTP and signals for cell death. Cytochrome C forms a complex with ____ which activates a cascade of caspase proteases
Cytochrome C
Apaf-1
