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| ==Types== | ==Types== | ||
| *''']s''' require oxygen |
*''']s''' require oxygen in order to survive and multiply. In a process known as ], these organisms use oxygen to ] substrates (for example ]s and ]s) in order to obtain ]. | ||
| *''']''' |
*In spite of their name, ''']''' may use oxygen, but also have ] methods of energy production. | ||
| *''']s''' are |
*''']s''' are facultative anaerobes that may use oxygen only at low concentrations. They may or may not be harmed by higher concentrations. | ||
| *''']''' |
*''']''' anaerobes are anaerobes that do not use oxygen but they are not harmed by it. | ||
| *''']s''' are anaerobes that do not use oxygen and they are harmed by it. | |||
| ==Glucose== | ==Glucose== | ||
| A good example would be the oxidation of ] (a ]) in ]. | A good example would be the oxidation of ] (a ]) in ]. | ||
Revision as of 22:57, 27 June 2013
1: Obligate aerobic bacteria gather at the top of the test tube in order to absorb maximal amount of oxygen.
2: Obligate anaerobic bacteria gather at the bottom to avoid oxygen.
3: Facultative bacteria gather mostly at the top, since aerobic respiration is the most beneficial one; but as lack of oxygen does not hurt them, they can be found all along the test tube.
4: Microaerophiles gather at the upper part of the test tube but not at the top. They require oxygen but at a low concentration.
5: Aerotolerant bacteria are not affected at all by oxygen, and they are evenly spread along the test tube.
An aerobic organism or aerobe is an organism that can survive and grow in an oxygenated environment. Facultative anaerobes grow and survive in an oxygenated environment and so do aerotolerant anaerobes.
Types
- Obligate aerobes require oxygen in order to survive and multiply. In a process known as cellular respiration, these organisms use oxygen to oxidize substrates (for example sugars and fats) in order to obtain energy.
- In spite of their name, Facultative anaerobes may use oxygen, but also have anaerobic methods of energy production.
- Microaerophiles are facultative anaerobes that may use oxygen only at low concentrations. They may or may not be harmed by higher concentrations.
- Aerotolerant anaerobes are anaerobes that do not use oxygen but they are not harmed by it.
- Obligate anaerobes are anaerobes that do not use oxygen and they are harmed by it.
Glucose
A good example would be the oxidation of glucose (a monosaccharide) in aerobic respiration.
Oxygen is used during the oxidation of glucose and water is produced.
This equation is a summary of what actually happens in three series of biochemical reactions: glycolysis, the Krebs cycle, and oxidative phosphorylation.
Diversity
Yeast is an example of a facultative anaerobe, which can develop in the presence of oxygen but does not require it. Individual human cells are also facultative anaerobes: they switch to lactic acid fermentation if oxygen is not available. However, for the whole organism this cannot be sustained for long, and humans are therefore obligate aerobes.
See also
- Aerobic digestion
- Anaerobic digestion
- Facultative anaerobic organism
- Fermentation (biochemistry)
- Microaerophile
- Obligate anaerobe
References
| Microbiology: Bacteria | |||||||
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| Medical microbiology | |||||||
| Biochemistry and ecology |
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| Shape | |||||||
| Structure |
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| Taxonomy and evolution | |||||||
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