1. Anaerobic Respiration and Fermentation
Chapter 3.3
McGraw-Hill Ryerson
Biology 12 (2011)

2. Anaerobic Respiration
Aerobic Respiration: catabolic pathways that require oxygen
Anaerobic respiration: catabolic pathways that exclude oxygen

3. Fermentation Occurs when there is an absence of oxygen
NADH that is reduced in glycolysis can’t be reoxidized by electron transport
Fermentation provides a different route for NADH to be reoxidized so that glycolysis can continue
2 common pathways are lactate fermentation and alcohol fermentation

4. Lactate Fermentation
Occurs in some single-celled organisms as well as some animal muscle cells that are temporarily without oxygen
Pyruvate generated by glycolysis reacts with NADH to rexodize it to NAD+ and ends up as lactate.
Lactate is acidic and will cause the surrounding environment to have a lower pH
Oxygen required to eliminate lactate in muscle cells is oxygen debt
 burning feeling when people run

5. Alcohol Fermentation
Some organisms can function in both aerobic and anaerobic environments
facultative anaerobes
When in anaerobic environments, they convert pyruvate to ethanol and CO2.
Used in baking bread and brewing alcohol

6. Homework
Pg. 137 #1, 3, 4, 5, 7, 9