Photosynthesis refers to the process whereby light is transformed into food for the plant. In plants photosynthesis occurs in the form of photosystems, in which different processes take place. One such system is aerobic respiration. This involves the conversion of light energy to a chemical energy, which is the fuel for the aerobic metabolism. The source of energy in this process is the sun.
Photosystems in plants are complex systems involving millions of interacting partners. Many of these partners have roles in the overall functioning of the photosynthetic reaction, but some are involved only in making the specific chemical reactions needed for photosynthesis. Photosystems involving only one partner are called an autotrophic photosystem, whereas Photosystems with many partners are called autotrophic respiration.
There are many different ways in which light can be transformed to usable energy in the photosynthetic pathways. Some of the key ingredients required are a catalyst, which stimulates the reaction, an enzyme or a set of enzymes, a catalyst group and a control enzyme. In the broadest sense, the catalysts can be any form of light, while in a more detailed one they can be either a free radical such as oxygen or a charged one such as hydrogen, or a neutral one such as carbon.
Light can be categorized according to its absorption and distribution. The absorption is measured by the absorbance, which can be expressed as the percentage of incident light absorbed, and by the illumination, which are the amount of light absorbed. The distribution of light is described by the intensity, which is a measure of how scattered the light is. In photosystems that involve photosynthetic reactions, the intensity of light distribution can be influenced by the concentration and the type of the catalyst.
When light is incident on a compound, it will undergo a reaction known as absorption. This reaction will release either an electron from an atom or a proton from an atom, depending on which kind of atom is involved. The electron from the atom or proton is transformed into a more energetic form called a light photon, which can then be absorbed by an electron in an area of the molecule that is excited by the photon.
Photosystems can be characterized according to the way in which the light is distributed after being incident upon them. The direction of the incident light wave is called the ‘field’ and the ‘photon’ that are released as a result of the reaction is termed as the ‘photon emission.’ The concentration of the light particles is known as the concentration, and this can be measured in terms of the luminous efficacy, which is the ratio of the total number of photons per unit of concentration. In a photo synthesis, the number of atoms that undergo the absorption process is known as the concentration. The reason why different wavelengths of light have different effects on atoms is due to the fact that certain wavelengths can only pass through certain types of solute structures.
The way in which light reacts to a solute is known as photoinduced reaction. A photoinduced reaction is also known as a ‘reaction’ because the products of the reaction are usually contained in the medium where the reaction takes place. Some examples of photoinduced reactions are the absorption of some ultraviolet rays and the reaction of chlorine and hydrogen. The absorption of x-rays is known as photoinduced absorption, while the reaction of hydrogen with chlorine is referred to as photoinduced chlorination. The absorption of visible light is called photoinduced transference, while that of ultraviolet light is called photoinduced luminescence.
Photosynthesis uses light to create a solution, which in turn can be changed into any of the substances listed above. In a photocell, as a rule, one atom of a molecule is replaced by an identical atom of another molecule with a different density. When the two molecules are excited to a higher level, they will combine and emit light. This process is very common in biology, and it is the basis for many of the chemical reactions that we observe in nature.