11.1 Chemiosmotic Theory Flashcards
How many ATP does one glucose produce?
32 ATP
How many ATP from glycolysis? What steps?
Net gain of 2 (7 and 10)
How many GTP from CC? What step?
Net gain of 2 (Step 5)
Where does the other ATP come from?
Most ATP comes from oxidative phosphorylation
Powered by chemiosmosis
What are the reductants produced from one glucose? What are they used for?
10 NADH and 2 FADH2; Used to reduce O2 to H2O
What do redox reactions do? Why?
Power the pumping of protons to establish a gradient across the inner mitochondrial membrane
What does the gradient allow for?
Generation of ATP
What is chemiosmosis?
chemical osmosis
What are the 6 major parts of the mitochondria?
Outer membrane, inner membrane, intermembrane space, Crista, mitochondrial matrix, and ATP synthase complexes
Crista
fold of inner membrane, increases surface area
Where are ETC proteins and ATP synthases located?
Embedded in inner membrane
How many membranes does mitochondria have?
2; inner and outer
Mitochondrial matrix
Aqueous interior where citrate cycle happens
What are redox rxns coupled to?
Electron transport
What does Redox energy fuel?
ETC proteins that pump protons across membrane
– Establish a H+ gradient
– Chem and electrical gradient
Where do protons go?
H+ flow through ATP synthase; Produces ATP
What is the N side?
Matrix; negative side of membrane
What is the P side?
Where protons are pumped; intermembrane space
What does the amount of mitochondria per cell depend on?
Energy needs
Slow twitch
need aerobic energy for long periods; More mitochondria; dark meat
Fast twitch
need aerobic energy in short bursts; Less mitochondria; white meat
What do plants have that are like mitochondria?
Chloroplasts
What are key differences between chloroplasts and mitochondria? (4)
-Thylakoid membrane not IMM
-Light energy used not redox
-Proton circuit is flipped relative
-Photosystem I/II not ETC proteins
What does the Electron transport system do?
Builds proton gradient
What does H+ gradient do?
stores potential energy generated by ETC
What is ATP synthase?
motor that performs the work
Which way do protons go due to Chemiosmosis?
protons flow in one direction due to charge
Uncouplers
allow proton circuit to continue,but not through ATP synthase
– Divert flow through an alternate route
Inhibitors
block proton circuit – Stop proton flow altogether
What are two examples of uncouplers?
Thermogenins and 2,4-DNP
Thermogenin proteins
Divert H+ flow away from ATP synthase
– Allow H+ to flow without ATP synthesis
– Energy converted to heat
2,4-Dinitrophenol
Popular anti-obesity drug in the 1930s
– Shifts the proton electrochemical gradient
– Potential energy dissipates as heat, instead of being converted to ATP
-Bad side effects
Oligomycin
Antibiotic that inhibits ATP synthase
Proton flow back into matrix stopped
– Build up of H+ in intermembrane space = very low pH
– Lack of H+ in matrix = very high pH
– No production of ATP
– Cell death
What are the Electron transport chain proteins (IMM)?
-Complex I: NADH–ubiquinone oxidoreductase
* (NADH dehydrogenase)
– Complex II: succinate dehydrogenase
– Complex III: ubiquinone–cytochrome c oxidoreductase
– Complex IV: cytochrome c oxidase
What complex does ATP synthesis?
ATP synthase complex (IMM)
