Transcript Chapter 9. Cellular Respiration STAGE 1: Glycolysis

Anaerobic Respiration
Stages:
1. Glycolysis
2. Fermentation
yeast
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2006-2007
Anaerobic Respiration
Cellular Respiration (harvesting ATP from
glucose) in the absence of Oxygen.
1. Bacteria that live in oxygen-free places
2. Some organisms that are exposed to
oxygen, but switch to fermentation
when oxygen is scarce.
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Glycolysis
Convert:
glucose (6C) to
2 pyruvate (3C)
 produces:
4 ATP & 2 NADH
 uses:
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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FERMENTATION
Fermentation does not yield any more ATP
than the tiny amount supplied by Glycolysis
It simply regenerates NAD, to refuel
Glycolysis.
1. This is plenty of ATP for small anaerobic
organisms
2. Not enough for large, multi-celled
organisms
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Lactate Fermentation
-Occurs in some
bacteria AND animals
for a quick fix of ATP
-Regenerates 2 NAD
-Produces 2 Lactates
(Lactic Acids)
pyruvate  lactic acid
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3C
NADH
3C
NAD+
back to glycolysis
Alcoholic Fermentation
-Occurs in bacteria,
some plants, AND
some fungi (like yeast)
for a quick fix of ATP
-Regenerates 2 NAD
pyruvate  ethanol + CO2
3C
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NADH
2C
NAD+
-Produces 2 Ethanol
(Alcohol) and
2 Carbon Dioxides
1C
back to glycolysis