Anaerobic respiration



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The dispute is about Lactic acid fermentation.
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See also: Fermentation (biochemistry)

Anaerobic respiration (anaerobiosis) refers to the ATP using an electron transport system and ATP synthase. Definition of anaerobic respiration: the breakdown of food substances in the absence of oxygen with a small amount of energy. General word and symbol equations for the anaerobic respiration of glucose can be shown as

ATP);
C6H12O6 \to 2C3H6O3 + 2 ATP.

The energy released is about 120 kJ per mole glucose.

Obligate anaerobes

In some organisms called ion (OH-), and other toxic molecules. .

Facultative anaerobes and obligate aerobes

catalase) that can safely handle these products and transform them into harmless water and diatomic oxygen in the following reactions:

2O2- + 2H+ –superoxide dismutase–> H2O2 (hydrogen peroxide) + O2.

The hydrogen peroxide produced is then transferred to a second reaction:

2H2O2 –catalase–> 2H2O + O2.

The oxidative powers of the superoxide ion have now been neutralized. Only facultative anaerobes and obligate aerobes possess the two enzymes necessary to reduce the superoxide.

In organisms which use ethanol.

Fermentation in animals is essential to human life.

In lactic acid fermentation, the following reaction occurs:

1. Glycolysis

C6H12O6 (glucose) + 2 NAD+ \to 2 C3H4O3 (pyruvic acid) + 2 NADH

2. Lactic acid creation

2 C3H4O3 (pyruvic acid) + 2 NADH \to 2 C3H6O3 (lactic acid) + 2 NAD+

Net reaction:

C6H12O6 (glucose) \to 2 C3H6O3 (lactic acid)


Fermentation in other organisms

In some plant cells and yeasts, fermentation produces CO2 and ethanol. The conversion of pyruvate to NAD+.

Anaerobic respiration in prokaryotes

In the field of prokaryotic fermentation the oxidation of molecules is coupled to the reduction of an internally-generated electron acceptor, usually pyruvate. Hence, scientists who study prokaryotic physiology view anaerobic respiration and fermentation as distinct processes and therefore do not use the terms interchangeably.

In anaerobic respiration, as the electrons from the electron donor are transported down the ATP synthase. Possible electron acceptors for anaerobic respiration are nitrate, nitrite, nitrous oxide, oxidised amines and nitro-compounds, fumarate, oxidised metal ions, sulfate, sulfur, sulfoxo-compounds, halogenated organic compounds, selenate, arsenate, bicarbonate or carbon dioxide (in acetogenesis and methanogenesis). All these types of anaerobic respiration are restricted to prokaryotic organisms.

Examples of anaerobic respiration

glucose + 3NO3- + 3H2O \to 6HCO3- + 3NH4+, ΔG0' = -1796 kJ
glucose + 3SO42- + 3H+ \to 6HCO3- + 3SH-, ΔG0' = -453 kJ
glucose + 12S + 12H2O \to 6HCO3- + 12HS- + 18H+, ΔG0' = -333 kJ

All of these terminal electron acceptors are further upstream in the electron transport chain, compared to O2. Consequently, anaerobic respiration is less effective than aerobic respiration. The ΔG0' of aerobic respiration is -2844 kJ.

Commercial applications of anaerobic respiration

v • d • e
Ethanol Formation
v • d • e
Anabolism

Aerobic)

Iron metabolism
 
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