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Bio102: Introduction to Cell Biology and Genetics
Anaerobic Respiration
Key Terms:
Anaerobic Respiration
Lactate Fermentation
Alcoholic Fermentation
Phosphofructokinase
Feedback Inhibition
Key Questions:
 How are all the parts of aerobic respiration connected together?
 What is the key problem that must be solved for a cell to survive anaerobically?
 How is respiration commonly regulated? Why might a cell want to slow down respiration?
Lecture Outline:
Anaerobic Metabolism
recall that in glycolysis
no oxygen required
2 ATP generated (net) per glucose
but there's an NAD+/NADH problem!
continuous running of glycolysis will use up all of your NAD+
need a means to NADH  NAD+
Fermentation
Purpose is to get rid of NADH to allow glycolysis to continue
1) alcoholic fermentation
pyruvate  ethanol & CO2
in plants and fungi (like yeasts)
both ethanol and CO2 are useful byproducts
2) lactate fermentation
pyruvate  lactate
in animals (like people)
waste product: lactate (lactic acid) or ethanol (alcohol)
Aerobic metabolism = glycolysis + citric acid cycle + electron transport + oxidative phosphorylation
Anaerobic metabolism = glycolysis + fermentation (lactate or alcoholic)
Regulation of Metabolism
Allosteric regulation of phosphofructokinase by ATP -- feedback regulation
Regulation by substrate concentration
Alternative energy sources
carbohydrates other than glucose
lipids
proteins