3.6-7: Oxidative Phosphorylation (ETC And Chemiosmosis) Flashcards
Where is the ETC located?
Inner membrane of the mitochondria (cristae)
What are cytochromes?
Iron based proteins
The ETC is a collection of ____
Proteins
Generally speaking, what occurs in the ETC in terms of electrons?
- as the electrons “fall” proteins alternate between reduced (accepts e) and oxidized (donates e) state
The cristae increases surface area for the reaction to occur. It does not produce ATP directly. How does the cristae help manage the release of energy then?
- it creates several small steps for the “fall” of electrons
We know that the final electron acceptor is oxygen. What does it pairup with to form H20?
- each oxygen pairs with 2H+ and 2 electrons
What is one MAJOR fucntion of ETC?
- create a proton (H+) gradient across the membrane
How do the proteins help in creating a proton gradient? (3)
- As proteins shuttle electrons across the ETC, they also pump H+ into the intermembrane space
- Use the exergonic flow of electrons from NADH and FADH2
- This gradient will power chemiosmosis
— use hydrogen ions to power cellular work
What is ATP synthase?
- The enzyme that makes ATP from ADP + P
Where does ATP synthase use energy from?
- from the H+ gradient across the membrane (using PMf)
How exactly does chemiosmosis work, in regards to ATP synthase? (3)
- H+ ions flow down their gradient through ATP Synthase
- ATP synthase acts like a rotor - When H+ binds, the rotor spins
- Activates catalytic sites to turn ADP + P into ATP
How many ATP is produced PER GLUCOSE after chemiosmosis?
-26-28 ATP
Quick check: How is a proton gradient formed across the inner mitochondrial membrane?
- The exergonic flow of electrons from NADH and FADH2 powers the complexes in the ETC to pump H+ into the inter-membrane space
