Oxidative Phosphorylation Flashcards
What is oxidation
Reduced electron carriers (NADH, FADH2) are re-oxidized and electrons are passed to O2, generating H2O
What is phosphorylation
Some of the free E released during oxidation is harnessed to drive the phosphorylation of ADP into ATP
Where does oxidative phosphorylation occur
inner mitochondrial membrane
What are the components of the electron transport chain
Complexes 1-4, coenzyme Q, Cytochrome C
What are Co Q and Cyt C
Mobile electron carriers
How do electrons move through the ETC
Spontaneously, series of linked redox reactions. Move from molecules with low reduction potential/affinity for e’s to high (O2 has highest; terminal electron acceptor)
How many protons are pumped across the inner mitochondrial membrane by 1 NADH, from which complexes
4 via complex 1, 4 via complex 3, 2 via complex 4 = 10 total
What is the importance of pumping H across the inner mitochondrial membrane
Movement of e’s through ETC is linked, can’t move electrons without it
How many H+ are needed per ATP synthesized via ATP synthase
Approx 3
What are the two portions of ATP synthase/their functions
F0 = transmembrane protein, protons pass through, triggers conformational change in F1
F1 = catalytic portion, synthesis of ATP from ADP + Pi
What determines proton movement and O2 consumption
Rate of ATP synthesis
How is the potential energy of the H+ gradient converted
To mechanical energy then chemical energy in ATP
What complex is Succinate Dehydrogenase, what is its role
Complex 2. Catalyzes oxidation of succinate to fumarate as part of the CAC. Electrons from succinate transferred to Co Q
How many protons is FADH2 associated with pumping
6 = 4 via complex 3, 2 via complex 4
What is the adenine nucleotide translocase & the Pi-H symporter
ANT = exports ATP from matrix into cytosol to drive energy-requiring processes, brings ADP back into matrix Pi-H = brings Pi and H back into matrix
