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This definition distinguishes fermentation from aerobic respiration, where oxygen is the acceptor, and types of anaerobic respiration where inorganic compound is the acceptor. [citation needed] Fermentation had been defined differently in the past. In 1876, Louis Pasteur defined it as "la vie sans air" (life without air). [7]
Anaerobic respiration is used by microorganisms, either bacteria or archaea, in which neither oxygen (aerobic respiration) nor pyruvate derivatives (fermentation) is the final electron acceptor. Rather, an inorganic acceptor such as sulfate ( SO 2− 4 ), nitrate ( NO − 3 ), or sulfur (S) is used. [ 16 ]
The terms aerobic respiration, anaerobic respiration and fermentation (substrate-level phosphorylation) do not refer to primary nutritional groups, but simply reflect the different use of possible electron acceptors in particular organisms, such as O 2 in aerobic respiration, or nitrate (NO − 3), sulfate (SO 2−
In aerobic respiration, oxygen is required. Using oxygen increases ATP production from 4 ATP molecules to about 30 ATP molecules. In anaerobic respiration, oxygen is not required. When oxygen is absent, the generation of ATP continues through fermentation. There are two types of fermentation: alcohol fermentation and lactic acid fermentation.
Anaerobic cellular respiration and fermentation generate ATP in very different ways, and the terms should not be treated as synonyms. Cellular respiration (both aerobic and anaerobic) uses highly reduced chemical compounds such as NADH and FADH 2 (for example produced during glycolysis and the citric acid cycle) to establish an electrochemical gradient (often a proton gradient) across a membrane.
Numerous fermentation pathways exist such as lactic acid fermentation, mixed acid fermentation, 2-3 butanediol fermentation where organic compounds are reduced to organic acids and alcohol. [8] [4] The energy yield of anaerobic respiration and fermentation (i.e. the number of ATP molecules generated) is less than in aerobic respiration. [8]
They gather mostly at the top because aerobic respiration generates more ATP than either fermentation or anaerobic respiration. 4: Microaerophiles need oxygen because they cannot ferment or respire anaerobically. However, they are poisoned by high concentrations of oxygen. They gather in the upper part of the test tube but not the very top.
[1] [2] In this type of respiration, oxygen serves as the terminal electron acceptor for the electron transport chain. [1] Aerobic respiration has the advantage of yielding more energy (adenosine triphosphate or ATP) than fermentation or anaerobic respiration, [3] but obligate aerobes are subject to high levels of oxidative stress. [2]