The Phytochemistry , where chemistry of the Vegetable , is the science which studies the structure, the metabolism and the function as well as the methods of analysis, of purification and extraction of natural substances resulting from the plants. It is indissociable other disciplines such as the Pharmacognosie (of the Greek: pharmacon, drug and gnôsis, knowledge) treating raw materials and substances with medicamentous potentiality of biological origin.

The plants are organization S Autotrophes which can synthesize a great number of complex organic molecules which do not intervene in the great ways of the basal Metabolism, i.e. the energy metabolism and the metabolism of carbonaceous . These molecules are however useful for the plants themselves and the consumers of the food chains for various reasons. The plants which have energy and of carbonaceous skeletons in sufficient quantity, thanks to the Photosynthèse, prove to be general-purpose producers.

General information on the vegetable metabolism

Vegetable cell

The vegetable cell is a highly complex system compartmentalized by membranes. This allows a distribution diversified of work within the cell. This delimitation in compartments requires a coordinated control of the Perméabilité of the barriers. Moreover, the regulation of various activities in the various compartments or organoids is necessary to the harmonization of the functions of the cell.

In biology, the structure and the function are always closely dependant. Techniques of cellular fractionation and insulation of the organoids or membranes have made it possible to study the specific functions of each compartment.

The Noyau (Nucleus) is the organoid which gave its name to the Eucaryote S (have = true, caryon = core). It contains the genetic information coded in the molecule of DNA (DNA).

; The cytosol The space delimited by the plasmalemme and the tonoplaste is called protoplasm . The cytoplasm corresponds to the space located apart from the cellular organoids. To avoid any confusion with the protoplasm which includes the organoids this “plasma fundamental” cytosol is called. The Protéines account for 20% of the mass of the cytosol. The observation with the Electron microscope of the cytosol reveals that it is not completely deprived of structure. It, indeed, is crossed by the cytosquelette made up of filamentous and contractile elements. The cytosquelette confers a stable form on the cytosol; it is also at the origin of the intracellular motility (cytoplasmic currents, displacement of organoids, anaphase and telophase of the Méiose…).

; Mitochondries The Mitochondries (mitochondrion) are organoids in the shape of sticks or filaments, sometimes ramified, a length of some micrometers and of a diameter of 7µm approximately. They can be observed with the optical Microscope. The mitochondries are involved in the cytoplasmic currents of the cytosol and their form can be modified. The number of these organoids varies according to the type and the function of the cell, it reflects in made the energy need of the cells. For example, the parenchymatous cells of the Xylème, in which the work of transport is important, are particularly rich in mitochondries. It is the same for the cells of the sifted tubes and the glandular cells (see vegetable Histologie). The mitochondries have a external membrane which plays the part of envelope, and a membrane interns whose surface interns strongly increased watch of the heads of ATP-synthétases. Between the two membranes inter-membrane space exists a which contains an aqueous solution. The external membrane is almost permeable with all the molecules of molecular weight lower than 10 KDa. The internal membrane is on the other hand very selective and delimits the internal space of mitochondrion, the matrix .

Glycolysis