Electron Transfer Chain Flashcards
What is electron transfer chain?
• It is a series of compounds— mainly proteins located in the inner mitochondrial membrane
• compounds are ordered from increasing electronegativity
What is broken down in ETC
NADH and FADH2 are converted into ATP
How does the ETC work?
• NADH and FADH2 are stripped of their electrons, forming NAD+ and FAD.
• These electrons are shuffled down the series of proteins, stripping them of the energy
• the energy is used to pump H ions from the matrix to the inner membrane space
• As the H ions built up, they’re eventually released back into the matrix, creating ATP.
• 1 PROTON = 1 ATP
Steps for breaking down NADH
1) NADH dehydrogenase removes H+ and electrons from NADH, which are carried along the chain
2) Electron carriers such ubiquinone (Q) and cytochrome (C) move electrons and H+ down the chain
3) At the end of the chain lays the cytochrome oxidase complex, which is a enzyme that catalyzes the reaction between protons, electrons and oxygen forming h2o
Why is oxygen important in the ETC
Oxygen is the final electron acceptor in the series, as it has the strongest electronegativity— capturing any electrons. This prevents a buildup of electrons and allows the cabin to run smoothly
NADH vs FADH2
NADH is donates electrons to the first protein complex (NADH dehyrdogenase), and as the electrons move from each protein complex, they pump and produce a proton each time, thus it will produce 3 protons per NADH
FADH2 skips the first complex and starts at the second protein complex (cytochrome b-c1), thus only pumps and produces 2 protons per FADH2
What problem does NADH face?
NADH made during glycolysis can cross the mitochondrial membrane, but not the inner membrane. To get the electrons from the two NADH molecules produced into the matrix, a shuffle system called glycerol phosphate, takes the electrons from NADH and gives the to FAD to make FADH2. Therefore, NADH from glycolysis makes 2 ATP molecules and not 3
