The two anaerobic metabolic pathways that some organisms use to generate ATP
- Anaerobic Respiration
2. Fementation
Anaerobic Respiration
Essentially the same as aerobic respiration except an inorganic molecule other than O2 is the electron acceptor at the end of the ETC.
Example of alternative electron acceptors are
what do bacteria and archaea use them to produce
NO3 (nitrate) =Nitrogen gas,
Sulphate= Hydrogen Sulphate
Co2 = Methane Gas ( CH4)
The number of ATP generated per molecule of glucose depends on what
The electron acceptor at the end of the ETC ( anaerobic always yield less than aerobic)
Example of greenhouse gasses
Co2 and methane Ch4
Organisms that use fermentation
Acquire ATP only from Glycolysis
Some microorganisms
Aerobic Respiration vs Fermentation
In FERMENTION Glycolysis still yields 2 ATPS, 2 NADH , 2 molecules of pyruvate per molecule of glucose.
Nadh does not donate its electrons to an electron transport chain.
Pyruvate is not further oxidized.
What happens to the electrons and Nadh produced in glycolysis
Nadh reduces pyruvate producing NAD+ so that glycolysis can continue ( 2 NAD+ and 2 H+= 2 NADH)
N0 additional ATP is generated.
BEcause of the inefficiency of fermentation where do most fermenters live
microorganisms live in sugar rich environments
Alcoholic Fermentation produces
Ethanol
The steps of Alcoholic Fermentation
- Pyruvate is converted to acetaldehyde and Carbon dioxide
2. Nadh reduces acetdehyde to produce NAD+ and etanol
Lactic acid fermentation
NADH is used to reduce pyruvate .
The products are 3 carbon compounds ( lactic acid and NAD+
Lactic acid fermentation in Human muscles
during strenuous exercise after 02 is depleted, the mucle can only get ATP FROM GLYCOLYSIS ( The cells use lactic acid fermentation to generate NAD+ so that glycolysis can continue.
The recovery process afterLactic acid fermentation in Human muscles
liver cells convert lactic acid back pyruvate. Mitochondria then process the pyruvate as usual by aerobic respiration
