AP Biology 2007-2008

Cellular RespirationHarvesting Chemical Energy

ATP

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Cellular RespirationStage 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

ANAEROBIC/Fermentation(without Oxygen)

• Glycolysis• Lactic Acid Fermentation

or• Alcoholic Fermentation

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Glycolysis

glucose pyruvate2x6C 3C

That’s not enoughATP for me!

Breaking down glucose “glyco – lysis” (splitting sugar)

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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Begins With..

Ends With.. , 2 NADH,

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Energy Input Steps

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Energy Releasing Steps

Now Unstable

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Energy Releasing Steps, cont.

Now Unstable

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Convert: glucose (6C) to 2 pyruvate (3C)

produces: 4 ATP & 2 NADH

consumes:2 ATP

net yield: 2 ATP & 2 NADH

Key Points

ATP2

2

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Pyruvate is a branching pointPyruvate

O2O2

mitochondriaKrebs cycle

aerobic respiration

fermentationanaerobicrespiration

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Glycolysis summary endergonicinvest some ATP

exergonicharvest a little ATP & a little NADH

net yield2 ATP2 NADH

4 ATP

ENERGY INVESTMENT

ENERGY PAYOFF

G3PC-C-C-P

NET YIELD

like $$in the bank

-2 ATP