Ch 26 Aerobic respiration Flashcards
What is the final electron acceptor in aerobic respiration
Oxygen; so electrons don’t run around as free radicals
Most of ATP is made where?
Mitochondria
Stages of cellular respiration
- Glycolysis (2ATP 2 NADH 2 Pyruvate)
- Pre-kreb’s prep cycle
- Krebs cycle
- Electron transport chain
- Chemiosmosis with ATP synthase
What happens in stage two: pre-Krebs cycle? And loses what via what?
-Pyruvate (3C) —>acetyl CoA (2C) via coenzyme A (loss of carbon atom by carbon dioxide)
Purpose of stage two pre-Krebs cycle?
-Preps carbon molecule for Krebs cycle
-passes pyruvate into mitochondrial matrix
End products of stage two pre-Krebs cycle?
2 NADH
2 CO2
2 acetyl CoA
What happens in stage three Krebs cycle or citric acid cycle?
Acetyl-CoA —> citric acid
 then cycle continues in the ring
Purpose of stage three Krebs cycle:
Use the Carbon to generate more NADH & FADH2 , Some CO2 byproduct
Net yield of stages 2and 3 of cellular respiration:
6 CO2
2 ATP
8 NADH
2 FADH2
How many times do mitochondrial matrix reactions occur?
Twice: because of 2 acetyl Co-A’s
What happens in Stage 4: electron transport chain
Electron carriers deliver electrons which move along protein complexes in inner membrane of mitochondria. Electrons picked up by oxygen which makes water.
Purpose of stage 4: electron transport chain
-Creates electron gradient: high H+ in inter-membrane
-regenerate NAD+ and FAD (Oxidize NADH and FADH2)
What happens in Stage five: Chemiosmosis?
Protons move down electrochemical gradient across membrane at ATP synthase pump which creates ATP
ATP synthase pump requires how many H+ for each ATP?
Requires 3H+ for each ATP
NAD+ releases at which enzyme complex? How many ATP are generated by NADH?
Complex 1; 2.5 ATP
FAD releases at which enzyme complex? How many ATP generated by FADH?
Enzyme complex 2and 3; FADH= 1.5 ATP
How much ATP can you produce with FADH AND NADH?
2 FADH = 3 ATP
10 NADH = 25 ATP
Stage at four and five generate how much ATP And regenerate what?
-28 HTP: 3 from FADH2, 25 from NADH
-Generates electron transporters: 10 NAD+, 2 FAD
Total amount of ATP generated with cellular respiration (including glycolysis):
About 32 total ATP
What metabolic poisons can disrupt ATP production?
Cyanide
Uncouplers
How does cyanide disrupt ATP production?
Blocks parts of electron transport chain; prevents picking up of electrons and oxygen delivery so can’t create ATP= cell death
How do on couplers disrupt ATP production?
Disrupt oxidative phosphorylation; pokes holes in mitochondrial membrane which lets protons Go across the gradient without using ATP synthase =less ATP = cell death
What happens to pyruvate in aerobic respiration?
Pyruvate is oxidized to CO2 and H2O
