Chapter 11 - Oxidative Phosphorylation Flashcards
Chemiosmosis
ATP generation due to proton flow across a membrane in response to a concentration gradient
Proton Gradient
Created by pumping H+ outward from the mitochondrial matrix by protein complexes, powered by redox reactions
Electron Transport Chain
Series of membrane-embedded proteins that convert the energy of redox reactions to a proton potential
ATP Synthesis
Inward flow of H+ down the concentration gradient through membrane-bound ATP synthase complexes
Produces how many ATP
28 out of 32 ATP
Complex I
NADH-Ubiquinone Oxidoreductase, NADH + Q + 5Hn > NAD + QH2 + 4Hp
Complex II
Succinate Dehydrogenase, electron pair extracted from succinate oxidation by succinate dehydrogenase transferred to FAD, used to reduce Q to generate QH2
Complex III
Ubiquinone-Cytochrome c Oxidoreductase, QH2 + 2Hn + 2 Cytochrome c (oxidized) > Q + 4Hp + 2 Cytochrome c (reduced)
Complex IV
Cytochrome c Oxidase, accepts electrons from cytochrome c and donates them to oxygen to form water, 2 Cytochrome c (reduced) + 4Hn + 1/2O2 > 2 Cytochrome c (oxidized) + 2Hp + H2O
Net Reaction of NADH Oxidation
2NADH + 2H + 5ADP + 5Pi + O2 > 2NAD + 5ATP + 2H2O
Binding Change Mechanism
Conformational changes converted into the production of ATP from ADP and inorganic phosphate
ATP/ADP Translocase
Antiporter membrane transport protein that exports ATP and imports ADP
Phosphate Translocase
Membrane transport protein that imports inorganic phosphate and protons in the mitochondria
Malate Aspartate Shuttle
Enables NADH from glycolysis to transfer electrons into the ETC, found in liver cells, 32 ATP
Glycerol-3-phosphate Shuttle
Enables NADH formation in glycolysis by reducing FAD into FADH2, 30 ATP, found in muscle cells
Complex I pumps …
4 Protons
Complex II pumps …
0 Protons
Complex III pumps …
4 Protons
Complex IV pumps …
2 Protons
Q Cycle
Converts 2e- transport into two 1e- transfer, cytochrome c transport 1e- from complex III to complex IV
