Oxygen - the most important component of the existence of all life on Earth.Surprisingly, this element of our planet, though its concentration in the air, according to some scientists inevitably decreases is vospolnimo stock.Even more striking seems that it is synthesized from more than the available resources - water, sunlight and carbon dioxide.And the process is carried out this wonderful plant.
Of course, we are talking about photosynthesis - a wonderful creation of nature.Despite the fact that scientists have thoroughly studied this question, repeat the step of photosynthesis in vitro unrealistic today.
This process can be divided into two stages:
- light-dependent reactions of photosynthesis.
- dark phase of photosynthesis.
their name is quite clear that the first part of the process takes place in the light, that is, with the participation of sunlight.There it is only in the green leaves of plants, because they contain chloroplasts - specific elements in the membranes of which the synthesis of ATP - molecules in which energy is stored.
When photons hit the solar light to the leaves of the plants containing chlorophyll, converts the energy of sunlight into the energy molecule ATP, already mentioned above.Moreover, thanks to elimination of two hydrogen atoms from water molecules (which also occurs by using sunlight) formed NADPH molecule.Decomposition of the water molecule, devoid of two hydrogen atoms, remains with the free oxygen, which enters the atmosphere.Thus, the products of photosynthesis in the light phase - is:
- oxygen;
- energy molecule ATP;
- atomic hydrogen H2 NADP.
curious that the formation of oxygen in this process is not the ultimate goal.Rather, it is a side effect.Further there is a dark phase of photosynthesis or chemosynthesis, which are directly involved products of the first phase.Let us consider it in more detail.
Indeed, the goal of the process is not the generation of oxygen.The dark phase of photosynthesis takes place in a different part of the sheet - in its chloroplast stroma.At the end of the light phase the plant has time to stock up an impressive amount of energy molecules - ATP and NADP H2, therefore, participation of light is no longer necessary.It is through these molecules are synthesized organic elements.It is logical that the problem of the energy molecule ATP - the energy supply for the processes of synthesis, while the role of NADPH H2 - recovery.
the beginning of this phase, a molecule is oxidized reducing agent, thereby disappearing two hydrogen atoms which gives at the output net NADPH molecule.At the same time, ATP gives a phosphoric acid residue, turning into ADP.These two processes occur within the matrix of the sheet.The newly obtained molecules then return to the brink of the leaves, which makes it possible to repeat the whole process of the light phase.However, this is not a key process of photosynthesis, we only identified the cyclical and the sequence of operations that occur in the leaves.
The end product of this phase becomes glucose - organic compound is attributable to simple sugars.The first detailed description of the synthesis of this molecule could Melvin Calvin.It was found that both molecules examined under light phase - energy and reducing agent - in the fusion process.In addition, important elements for the formation of simple sugars are six molecules of carbon dioxide (CO2), 24 hydrogen atoms of water molecules 6:
6SO2 + 24N + ATP + C6H12O6 6N2O.
dark phase of photosynthesis important plants because except glucose are formed during the various amino acids, nucleotides, fatty acids and glycerol.
Photosynthesis - a highly unique natural process.He not only is the key to maintain a constant level of oxygen in the atmosphere and the ozone layer, but also represents the perfection of nature, when the inorganic elements are organic.
