Ch. 6 Cellular Respiration 6.11 – 6.13

Krebs cycle completes the oxidation of organic fuel, making many NADH & FADH 2 molecules Where does the Acetyl CoA come from to start the Krebs cycle? End of glycolysis, from the pyruvic acid Where does the Krebs cycle take place? In the mitochondrial matrix For every molecule of Acetyl CoA that enters Krebs cycle, what are the products? 1ATP, 1FADH 2, 3NADH How many enter? 2

Does glycolysis or Krebs payoff more energy? Krebs yields more potential energy even though glycolysis generates more net ATP. How is ATP made in Krebs? Substrate-level phosphorylation What do the FADH2 and NADH molecules do? They carry the high energy hydrogens from glucose to the ETC.

So, how many energy rich molecules has the cell gained from one molecule of glucose processed through glycolysis & Krebs? The cell has gained a total of: 4 ATP, 10 NADH, 2 FADH 2 How does the cell use the energy in NADH & FADH 2 ? It has to be converted to ATP & used immediately.

Chemiosmosis powers most ATP production Why is the mitochondrial membrane structure ideal for making ATP? The space in the phospholipid membrane allow the proteins of the ETC and ATP synthase to be embedded. How do the protein complexes transport H+ ions through membrane? Energy released as electrons pass from protein to protein.

Krebs- ch.7

How does this create a potential energy storage? H+ ions accumulate in the inner membrane space What effect would the absence of O2 have on the ETC? No chemiosmotic production of ATP, nothing to pull electrons, or harness NADH energy

Certain poisons interrupt critical events in cellular respiration How does Rotenone interrupt cell respiration? Blocks the electrons from passing from electron carrier molecules, no ATP is made. How does cyanide and carbon monoxide work? They block passage of electrons to O2, no ATP is made. Oligomycin stops what? The H+ ions from passing through ATP synthase, no ATP is formed…it is an antibiotic prescribed to combat skin fungal infections.