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The process of Photosynthesis In Plants - Photosynthesis is a biochemical process in which plants, algae, and some bacteria to produce energy in use (nutrients) using light energy. Nearly all living things depend on energy produced from photosynthesis. As a result of photosynthesis is very important for life on earth. Photosynthesis is also credited with producing most of the oxygen present in Earth's atmosphere.

Organisms that produce energy through photosynthesis (photos meaning light) is called fototrof. Photosynthesis is one way for the photosynthetic carbon assimilation of CO2 free carbon bound (fixed) to gulasebagai energy storage molecules. Another way to be taken is the organism to assimilate carbon through chemosynthesis, by some sulfur bacteria.

Until now photosynthesis was studied further because there are still a number of steps that can not be explained, even though it very much is known about this vital process. The process of photosynthesis is very complex because it involves all the main branches of the natural sciences, such as physics, chemistry or biology alone.

In plants, the main organ of photosynthesis is the site of the leaf. But in general, all the cells that have the potential to establish a chloroplast reaction. At the site of the photosynthetic organelle is, exactly in the stroma. Of photosynthesis (called photosynthate) is usually sent to a nearby tissues first. Basically, a series of reactions of photosynthesis can be divided into two main parts: the light reaction (because it requires light) and dark reactions (do not require light but require carbon dioxide).

Light reaction

Light reaction is a process to produce ATP and reduction NADPH2. This reaction requires water molecules. The process begins with the capture of photons by the antenna pigments.
Chlorophyll pigments absorb more visible light to blue (400-450 nanometers) and red (650-700 nanometers) than green (500-600 nanometers). The green light will be reflected and captured by our eyes causing a sensation that the leaves are green. Photosynthesis will produce more energy at a particular wave length of light. This is because the shorter wavelengths greater energy savings.

In the leaves, the light is absorbed by chlorophyll molecules to be collected at the reaction centers. Plants have two types of pigments that function as active as the reaction center or photosystem II and photosystem I. Photosystem Photosystem II consists of chlorophyll molecules that absorb light with a wavelength of 680 nanometers, 700 nanometers whereas photosystem I. The two photosystems this will work simultaneously in photosynthesis, such as the two batteries in a flashlight that works mutually reinforcing.

Photosynthesis begins when light ionizes the chlorophyll molecules in Photosystem II, releasing electrons are transferred along the electron transport chain. The energy of the electron is used for photophosphorylation that produce ATP, the energy exchange in the cell unit. Photosystem II reaction causes a deficit or lack of electrons that must be replaced immediately. In plants and algae, the electron deficiency is filled by electrons from the ionization of water ionization occurs simultaneously with chlorophyll. The result is an electron ionization of water and oxygen.

Oxygen is only produced from the photosynthesis of water, instead of carbon dioxide. This was first revealed by C.B. Neil van who studied photosynthetic bacteria in the 1930's. Photosynthetic bacteria, in addition to cyanobacteria, use does not produce oxygen as it uses ionization or hydrogen sulfide.
At the same time the ionization photosystem II, photosystem I light also ionizes, releasing electrons are transferred along the electron transport chain which ultimately reduces NADP into NADPH.

Dark Reaction

ATP and NADPH produced by the photosynthetic process triggers a variety of biochemical processes. In plants, the biochemical triggers is the Calvin cycle that binds the carbon dioxide to form ribulose (and then into sugar such as glucose). This reaction is called the dark reactions because it does not depend on the presence or absence of light so that it can occur even in the dark (without light). (Hardianto, 30: 2004)