Cellular Respiration
Harvesting Chemical Energy
ATP
AP Biology
2007-2008
Cellular Respiration
Stage 1:
Glycolysis
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Cellular respiration is a process which generates energy in living
things.
It extracts stored energy from glucose to form ATP.
The energy stored in ATP can then be used to drive processes
requiring energy, including bio-synthesis, locomotion or
transportation of molecules across cell membranes..
There are two types of cellular respiration:
AEROBIC
(requires Oxygen)
• Glycolysis
• Krebs Cycle
• Electron Transport Chain
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ANAEROBIC/Fermentation
(without Oxygen)
• Glycolysis
• Lactic Acid Fermentation
or
• Alcoholic Fermentation
Glycolysis
 Breaking down glucose
“glyco – lysis” (splitting sugar)
glucose      pyruvate
2x 3C
6C



This is the beginning stage for both aerobic/anaerobic
It’s inefficient
 generate only 2 ATP for every 1 glucose
occurs in the cytoplasm of the cell
 right outside the mitochondria
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That’s not enough
ATP for me!
Begins
With..
Ends
APWith..
Biology
,
,
2 NADH
Energy Input Steps
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Energy Releasing Steps
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Now Unstable
Energy Releasing Steps, cont.
Now Unstable
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Key Points
Convert:
glucose (6C) to
2 pyruvate (3C)
 produces:
4 ATP & 2 NADH
 consumes:
2 ATP
 net yield:
2 ATP & 2 NADH

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2
2 ATP
Pyruvate is a branching point
Pyruvate
O2
O2
fermentation
anaerobic
respiration
mitochondria
Krebs cycle
aerobic respiration
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Glycolysis summary
endergonic
invest some ATP
ENERGY INVESTMENT
-2 ATP
ENERGY PAYOFF
G3P
C-C-C-P
4 ATP
exergonic
harvest a little
ATP & a little NADH
like $$
in the
bank
NET YIELD
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net yield
2 ATP
2 NADH