Anaerobic glycolysis is the transformation of glucose into lactate when a limited amount of oxygen (O 2 ) is available. Anaerobic glycolysis is only an effective tool for energy production during short and intense workouts, providing energy for a period ranging from 10 seconds to 2 minutes. Anaerobic glycolysis (lactic acid) system is dominant from about 10-30 seconds during maximal effort. It recharges very quickly during this period and produces 2 ATP molecules per glucose molecule or about 5% of the glucose energy potential (38 molecules of ATP). The speed at which ATP is produced is about 100 times that of oxidative phosphorylation.
Anaerobic glycolysis is considered the primary means of energy production in previous organisms before oxygen is at high concentrations in the atmosphere and thus represents a more ancient form of energy production in cells.
In mammals, lactate can be changed by the liver back into glucose; see the Cori cycle.
The fate of pyruvate under anaerobic conditions:
- Pyruvate is a terminal electron acceptor in lactic acid fermentation When sufficient oxygen is absent in muscle cells for further oxidation of pyruvate and NADH produced in glycolysis, NAD is regenerated from NADH by reduction of pyruvate to lactate. Pyruvate is converted to lactate by lactate dehydrogenase enzyme. The standard free-energy change of the reaction is -25.1 kJ/mol.
- Fermentation of ethanol Yeast and other anaerobic microorganisms convert glucose into ethanol and CO2 rather than pyruvate. Pyruvate was first converted into acetaldehyde by enzyme pyruvate decarboxylase in the presence of thiamine pyrophosphate and Mg. Carbon dioxide is released during this reaction. Acetaldehyde is then converted to ethanol by the enzyme alcohol dehydrogenase . NADH is oxidized to NAD during this reaction.
Video Anaerobic glycolysis
See also
- The lactate shuttle hypothesis
Aerobic Glycolysis
Maps Anaerobic glycolysis
References
Source of the article : Wikipedia
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