Primary nutritional groups
The material and energy exchange describes the diet of living organisms. The technical term is synonymous trophic status ( from Ancient Greek τροφή ( trophé ) = nutrition): All organisms need energy to maintain its life processes. And also need all earthly organisms carbon they see their environment and incorporate into endogenous biomass.
Among the many forms of life on earth, quite different material and energy exchange can be found. Each trophic level is characterized here by three criteria.
Furthermore, all living things need certain extent thermal energy to initiate the biochemical reactions in their cells and to keep in progress. Otherwise, the life processes come to a halt. The provision of thermal energy is not taken into account in the criteria of the material and energy exchange. The making available of the thermal energy is therefore not a question for the trophic, but to the thermal unit (→ Ektothermie, endothermic, thermogenesis).
The characterization of the material and energy exchange has particularly outstanding importance for Microbiology. It is precisely within the micro-organisms evolved the Trophien to the utmost diversity. In addition, many of them have more than one metabolic type. In contrast to this kind much pages archaea, bacteria and protists, most multicellular organisms behave metabolically physiologically uniform: Green plants operate Photohydroautotrophie. Animals and fungi use Chemoorganoheterotrophie.
Trophic on the type of energy source: phototrophy, Radiotrophie, Chemotrophie
It is a power source needed to synthesize adenosine triphosphate ( ATP) primary. The cleavage of ATP and then provides the power for the structure of the biomass.
- Phototrophy: The metabolic energy comes from light. Typical phototrophic organisms are green plants.
- Radiotrophie: The metabolic energy comes from ionizing radiation. This form of trophic so far been proven only for melanin- containing fungi.
- Chemotrophie: The metabolic energy comes from exergonic conversion processes, such as redox reactions of certain chemical compounds. The chemotrophic metabolism forms include respiration and fermentation. Typical chemotrophe organisms are animals.
An electron source ( Elektronendon (at) or reducing agents ) needed to perform reduction in the course of the building change. As an electron carrier between the electron source and the materials of construction material change act nicotinamide adenine dinucleotide ( NAD) and nicotinamide adenine dinucleotide ( NADP ). Both molecules are reduced for this purpose to NADH or NADPH. The subsequent oxidation of NAD (P ) H ( back to NAD (P)) provides electrons for the later build-up of biomass.
- Lithotrophie: The electrons come from the oxidation of inorganic substances. Typical lithotrophe organisms have nitrifying bacteria. Hydrotrophie: The electrons come from the oxidation of inorganic substance water. Thus the Hydrotrophie is merely a particular form of Lithotrophie. However, it is pointed out separately because of their importance. Typical hydrotrope organisms are green plants.
Trophic on the nature of the carbon source: autotrophy, heterotrophy
It is a carbon source is needed in order to build the biomass.
- Autotrophy: The carbon comes from carbon dioxide (CO2), or from bicarbonate ions (HCO3-). Typical autotrophic organisms are green plants.
- Heterotrophy: The carbon comes from organic compounds. Typical heterotrophic organisms are animals.
Organisms that are capable of both autotrophy and heterotrophy to, operate mixotrophy.