Electron transport system and ATP synthesis Flashcards
How is a proton gradient created in the mitochondrion membrane?
From the energy stored in NADH
What purpose does the proton gradient have in the mitochondrion membrane?
Used to make ATP
What is NADH dehydrogenase?
An enzyme that takes the H+ from NADH molecules
- Oxidizes NADH
- Products: NAD+ + H+
What is the function of NADH dehydrogenase?
- Transfers electrons froman NADH to electron carrier (coenzyme Q) and then to the next protein
- Transfers the protons (H+) from the NADH out of the mitochondria and into the intermembrane space
Where do the electrons go from the first carrier molecule?
The electrons are transferred to the second protein and then to the second electron carrier,
- More H+ ions are released out of the mitochondria when an electron binds to the second protein pump
What happens once the electron carrier has given its electrons from the NADH to the second protein?
The second protein then receives the electrons of FADH2 molecules, keeping the electrons while the H+ protons leave the cell through the membrane
What does the second electron carrier do with the electrons it gained from the second enzyme?
The electrons are transferred from the electron carrier to the third and final enzyme of the chain,
- H+ ions are released out of the mitochondria through the enzyme when it receives the electrons
What happens to the electrons in the final enzyme/protein of the electron transport chain?
The enzyme transfers the electrons to oxygen, the last electron acceptor,
Products: H2O
How do the H+ ions get back into the mitochondria?
Through special channels called ATP synthase
How is ATP formed from the H+ ions that reenter the mitochondria?
The energy from the movement of the H+ ions are used to synthesize ATP from ADP + P_i
- Also known as oxidative phosphorylation
- This happens as the H+ ion crosses the ATP synthase
What is oxidative phosphorylation?
- Synthesis of ATP using oxygen and chemiosmosis
- The synthesis of ATP from H+ ions combined with ADP + Phosphate, while O2 is the final electron acceptor
What is ATP synthase?
Transmembrane protein that uses the movement of a proton (H+) to combine an ADP and inorganic phosphate to ATP
What is chemiosmosis?
The movement of ions across a membrane creates a concentration gradient that can be used to synthesize ATP
Simply describe the electron transport chain
The movement of electrons using electron carrier molecules and enzymes until the electron reaches a final acceptor.
- As an electron is accepted by an enzyme, a proton is pumped through the enzyme.
What is the inner-membrane space of a mitochondria?
The space between the inner and outer membranes
- Where H+ accumulate during the Electron transport chain
