Aerobic organism

Aerobie ( from Ancient Greek ἀήρ aer "air" ) refers to life, for the elemental oxygen (O2 ) is needed, which is the opposite of anaerobic.

Derived concepts in animals

As aerobes or aerobic as is known creatures that come to life elemental oxygen (O2) need. The oxygen is predominantly required for oxidative conversion processes in energy metabolism, such as in the respiration of higher organisms.

Creatures that prefer oxygen in only low concentrations, it is called microaerophilic.

Aerobic processes

In chemical processes are aerobic oxidations. If the oxygen supply is interrupted or a system based on oxidation system overwhelmed, anaerobic biochemical reactions, especially fermentation processes may predominate or fully gain the upper hand.

One example is the metabolism of muscles in humans. At low intensity, the energy is mainly aerobic oxidation of fatty acids and aerobic metabolism of glucose resulting from by way of glycolysis pyruvate or lactate.

If the muscle more stressed, the proportion of energy takes through glycolysis (see aerobic threshold ). The waste in growing amounts of lactate can, however, still - in glycolytic muscle fibers in small quantities, in good training condition especially in ST fibers and in cardiac muscle - are further metabolised, so that the blood lactate level does not increase excessively. Only when this need of the oxygen system is overwhelmed (which is not due to a lack of oxygen ) leads to a sharp increase in lactate (reaching the individual anaerobic threshold).

Also significant in this context gluconeogenesis in the liver is dependent on oxygen, since it consumes ATP.

Examples of aerobic processes:

  • Breathing
  • Composting
  • Nitrification

Because of its importance for many life processes oxygen is an important abiotic factor in ecology.

Occurrence in nature

This is known as oxygen-containing habitats oxic, anoxic habitats without oxygen. In habitats in which the oxygen content is different, we speak of oxic and anoxic zones. For example, the upper zone is bright and relatively well supplied with oxygen in the mud flats of the Wadden Sea. It provides an oxic zone Represents the redox potential is here above 100 mV ( millivolts). Oxygen can be detected chemically. This part of the silt Watts is extremely densely populated. In a few millimeters to centimeters depth changes its appearance: The Wadden looks black; the staining is caused by heavy metal sulphides, in particular by iron monosulfide ( FeS ). It occurs on a typical smell of hydrogen sulfide. The redox potential is below -200 mV here. Molecular oxygen is at best still detectable in trace amounts. In this anoxic zone only those creatures can exist that bring either make do without oxygen ( anaerobic ) or by special breathing organs ( in Sipho mussels ) or their behavior ( lugworm ) oxygen from the surface.

  • Ecological property
  • Microbiology
  • Metabolism