Download Fermentation

Fermentation
what you and cheese have in common
How To Make Energy Without Oxygen
● Glycolysis is anaerobic
○ If O2 is present,
pyruvic acid goes to
mitochondria for
aerobic respiration
○ If no O2 is available,
fermentation occurs
Fermentation
● Doesn’t make ATP
● Allows glycolysis to
continue making ATP
● Anaerobic
● 2 types of fermentation
○ lactic acid
○ alcoholic
Lactic Acid Fermentation
● Glycolysis produces:
○ 2 pyruvic acids
○ 2 NADH
○ 2 net ATP
● Without O2, the 2 NADH convert back to NAD+
● NAD+ allows glycolysis to continue
● Electrons released from NADH convert pyruvic acid
into lactic acid
Lactic Acid Fermentation
● For every glucose broken, you get,
○ 2 net ATP (from glycolysis)
○ 2 lactic acids (from fermentation)
● Lactic acid creates burn in muscles after long use
○ When O2 is added back to the cell, lactic acid
breaks down into pyruvic acid
○ When O2 is present, fermentation stops, and
respiration continues
Lactic Acid Fermentation
● Formula: pyruvic acid + NADH -> lactic acid + NAD+
● Some bacteria use lactic acid fermentation
● We use those bacteria to make food:
○ cheese
○ yogurt
○ pickles
○ sauerkraut
Alcoholic Fermentation
● Similar process to lactic acid
fermentation
● Instead of creating lactic
acid, the products are
○ ethyl alcohol
○ CO2
● HUMANS DO NOT DO
THIS!!!
Alcoholic Fermentation
● Formula: pyruvic acid + NADH -> alcohol + CO2 + NAD+
● Occurs in organisms like yeast
● We use yeast to make:
○ bread (holes in bread are from CO2)
○ alcohols