The metabolism is the whole of the molecular transformations and the transfers of energy which proceed in an uninterrupted way in the cell or the living organism. These is an ordered process, which utilizes processes of degradation (Catabolisme) and of organic synthesis (Anabolisme).

One can distinguish there the basal Metabolism and the metabolism in activity.

The anabolism is the metabolism which makes it possible the cell to synthesize the substances essential to its life and its function. This synthesis is carried out starting from the materials which the cell absorbed of the external medium and the energy released by catabolism or coming from outside (case of the Photosynthèse).

The metabonomic measurement the print of the biochemical disturbances caused by the diseases, the drugs or of the toxic products. Introduced into the years 1980, the métabonomique one (Nicholson and Al 1990) started to play a big role in R & D in the drug company only recently. This technology, complementary to genomic and proteomic, makes it possible for example to characterize the animal models of various pathologies in order to identify new pharmacological targets. The characteristic of metabonomic is the simultaneous analysis of a very great number of metabolites (small molecules resulting from the metabolism) in the biological environments such as the urine, plasma… Tools of screening (broad and systematic exploration) metabolic such as Nuclear Magnetic resonance and the Mass Spectrometry are used in order to identify markers (or series of metabolic markers = profiles) of toxicity, with an aim of detecting, early in the development cycle, the drugs candidates which will present undesirable effects. Ideally, the biomarqueurs identified in preclinic phase will be not-invasive and usable in clinical phase to follow release, the progression and the cure of a pathology. In order to identify new metabolites markers of toxicity, it is also necessary to know the variations known as “normal” of the metabolic pool (effect of the diurnal cycle, the stress, the food mode, the weight loss, etc). It is thus possible to discover the metabolic disturbances which are specific studied pathology.

Modes of transformation

The metabolism of degradation of grosses Molécule S in small molecules, which allows the release of energy, is called Catabolisme . Energy is put in reserve at the time of phosphorylation of ADP (adenosine diphosphate) in ATP (adenosine triphosphate). This energy will be used to provide the various functions of the cell. The ATP is formed starting from glucoses, lipids, and protids combined with oxygen. The formation of the ATP asks for a certain quantity of oxygen, therefore time.

Three operating processes exist for the muscles :

• anaerobic mode alactique : maximum energy but of short duration, the muscles degrade the ATP and give ADP reconstituted immediately in ATP  ;
• anaerobic mode lactique : average energy. The ATP is created without oxygen during the effort at the price of a fermentation giving the lactic acid; it can be synthesized in glucose by the liver;
• the aérobie  mode;: weak energy, normal breathing (phase of rest)   ; the fuels are diversified, the lactic acid of the muscles can be re-used like fuel.

See too

• Aerobic metabolism

• anaerobic Metabolism
• Life and radiation
• Mode and gastronomy

External bonds

• principal ways of the metabolism: a course of Interactive Biochemistry on Wikilivres

• flow chart off the major metabolic pathways (engl.)
• interactive metabolism, University P& Mr. Curie

Simple: Metabolism