Download Fermentation - Sacred Heart Academy

Fermentation
Sections 6.13-6.16
6.13 Fermentation
• Fermentation is a way of harvesting chemical
energy that does not require oxygen. Fermentation
– takes advantage of glycolysis,
– produces two ATP molecules per glucose, and
– reduces NAD+ to NADH.
• Fermentation must provide an anaerobic path for
recycling NADH back to NAD+.
© 2012 Pearson Education, Inc.
6.13 Lactic acid Fermentation
• Your muscle cells (when?) and certain bacteria
can oxidize NADH through lactic acid
fermentation, in which
– NADH is oxidized to NAD+ and
– pyruvate is reduced to lactate.
© 2012 Pearson Education, Inc.
Figure 6.13A
2 ADP
2 P
2 ATP
Glycolysis
Glucose
2 NAD
2 NADH
2 Pyruvate
2 NADH
2 NAD
2 Lactate
6.13 Lactic Acid Fermentation
• Lactate is carried by the blood to the liver, where
it is converted back to pyruvate and oxidized in
the mitochondria of liver cells.
• Bacteria: What foods are produced by lactic acid
fermentation?
© 2012 Pearson Education, Inc.
6.13 Fermentation
• Alcohol Fermentation
• In this process yeasts (single-celled fungi)
– oxidize NADH back to NAD+ and
– convert pyruvate to CO2 and ethanol.
• What foods are produced by alcohol
fermentation?
© 2012 Pearson Education, Inc.
Figure 6.13B
Glucose
2 NAD
Glycolysis
2 ADP
2 P
2 ATP
2 NADH
2 Pyruvate
2 NADH
2 CO2
2 NAD
2 Ethanol
6.13 Fermentation
• Obligate anaerobes
• Facultative anaerobes
© 2012 Pearson Education, Inc.
6.14 EVOLUTION CONNECTION: Glycolysis evolved early
in the history of life on Earth
• The ancient history of glycolysis is supported by
its
– occurrence in all the domains of life and
– Uses pathways that do not involve any membranebounded organelles.
© 2012 Pearson Education, Inc.
6.15 Cells use many kinds of organic molecules as fuel
for cellular respiration
• Although glucose is considered to be the
primary source of sugar for respiration and
fermentation, ATP is generated using
– carbohydrates,
– fats, and
– proteins.
© 2012 Pearson Education, Inc.
Figure 6.15
Food, such as
peanuts
Carbohydrates
Sugars
Fats
Proteins
Glycerol Fatty acids
Amino acids
Amino
groups
Glucose
G3P
Pyruvate
Glycolysis
Pyruvate
Oxidation
Acetyl CoA
ATP
Citric
Acid
Cycle
Oxidative
Phosphorylation