Transcript Cellular Respiration

Cellular Respiration
Aerobic and Anaerobic
Metabolism
Glycolysis takes place in the
cytoplasm
Glycolysis Simplified
(greatly )
If oxygen is available (aerobic), then
pyruvate enters the Krebs cycle
If oxygen is not available(anaerobic),
then pyruvate undergoes fermentation
Aerobic respiration
Synonymous Terms
• Krebs cycle
• Citric acid cycle
• Tri-carboxylic acid cycle
(TCA cycle)
Mitochondrial Structure
The Krebs cycle takes place across inner
membrane space (matrix) of the mitochondrion
ElectronTransport
The Role of Oxygen (O2)
Oxygen is the terminal
(final) electron acceptor
 Oxygen is needed
only in the very LAST
step of cellular
respiration!
½ O2 + 2H+ + 2e-  H2O
Mitochondrial Structure
Infoldings (cristae) increase the area of membrane
surface available for electron transport
Aerobic Respiration
C6H12O6 + 6O2 → 6CO2 + 6H2O + 38 ATP
 The Krebs cycle and electron transport
take place in the mitochondria
 The Krebs cycle and electron transport
maximize ATP yield
 38 ATP vs. 2 ATP for fermentation
Anaerobic Respiration
(Alcohol Fermentation)
C6H12O6 → 2 CH3CH2OH + 2 CO2 + 2 ATP
glucose
ethyl alcohol carbon
dioxide
Alcohol fermentation takes place in yeast
and some bacteria, and yields only the
2 ATP produced in glycolysis
Anaerobic Respiration
(Lactic Acid Fermentation)
C6H12O6 → 2 C3H6O3 + 2 ATP
glucose
lactic acid
Lactic acid fermentation takes place in
animal cells and some bacteria and fungi;
it yields only the 2 ATP produced in
glycolysis.