Transcript 9.3 Fermentation

9.3 Fermentation
Life without oxygen?
• Cellular respiration only
happens when oxygen
is present
• What happens if oxygen
isn’t available?
I. Fermentation
• Glycolysis quickly
produces ATP without
oxygen
• If too much ATP is made,
no more NAD+ are
available
– Eventually, no more ATP
can be made
• Electron chain only runs if
oxygen is present
I. Fermentation
• There is a pathway that can
make ATP without oxygen
• Fermentation: the process of
glycolysis and the anaerobic
pathway combined
• Without oxygen, fermentation
releases energy from food
molecules by producing ATP
I. Fermentation
• NADH becomes NAD+ by
giving electrons to pyruvic
acid
• NAD+ can then be used for
glycolysis again
• Fermentation occurs in
the:?????
A. Alcoholic Fermentation
• Yeasts and other microorganisms use alcoholic
fermentation
• Used to make bread and alcoholic beverages
• Formula:
Pyruvic acid + NADH
Alcohol + CO2 + NAD+
B. Lactic Acid Fermentation
• Most organisms & you, carry out lactic acid
fermentation
• Used in your muscles
• Give products like sour cream and yogurt their sour
taste
• Formula:
Pyruvic acid + NADH
Lactic acid+ NAD+
What does it look like?