BIO1011 Lecture Notes - Lecture 14: Lactic Acid, Pyruvic Acid, Carboxylic Acid
Cellular Respiration
Anaerobic Respiration
•Occurs when there is no accessible O2
•It is similar to aerobic respiration in that electrons extracted from a fuel molecule are
passed through an electron transport chain, driving ATP synthesis
•Some organisms use sulfate (SO42-) as the final electron acceptor at the end of the
ETC while others use nitrate ( NO3-), sulphur, or one of a variety of other molecules
•This system is often used by prokaryotes that live in low oxygen environments, such as
methanogens which are found in soils and digestive
systems
Fermentation
•Another anaerobic pathway for breaking down glucose
•The only energy extraction pathway is glycolysis
•The pyruvates produced in glycolysis do not continue
through oxidation, the citric aid cycle or ETC
Lactic Acid Fermentation:
-NADH transfers its electrons directly to
pyruvate, generating lactate as a byproduct
-Occurs in bacteria in yogurt, and muscles
Alcohol Fermentation:
-A similar process where
NADH donates its electrons to a
derivative of pyruvate, producing ethanol
-Produces the ethanol found in drinks like beer and wine
-It is a two step process:
-A carboxyl group is removed from pyruvate, releasing CO2
and producing acetyldehyde
-Then NADH passes its electrons to acetyldehyde,
regenerating NAD+ and forming ethanol
alcohol
lactic acid
Document Summary
Anaerobic respiration: occurs when there is no accessible o2, it is similar to aerobic respiration in that electrons extracted from a fuel molecule are passed through an electron transport chain, driving atp synthesis, some organisms use sulfate (so4. 2-) as the nal electron acceptor at the end of the. Fermentation: another anaerobic pathway for breaking down glucose, the only energy extraction pathway is glycolysis, the pyruvates produced in glycolysis do not continue through oxidation, the citric aid cycle or etc. Nadh transfers its electrons directly to pyruvate, generating lactate as a byproduct. Occurs in bacteria in yogurt, and muscles alcohol. Nadh donates its electrons to a derivative of pyruvate, producing ethanol. Produces the ethanol found in drinks like beer and wine. A carboxyl group is removed from pyruvate, releasing co2 and producing acetyldehyde.