Photosynthesis pathway

Cereals are divided according to the photosynthesis pathway into two groups ... 

Kinetic isotope effects are an important factor in the biology of deuterium. Isotopic fractionation of hydrogen and deuterium in plants occurs in photosynthesis. The lighter isotope is preferentially incorporated from water into carbohydrates and tipids formed by photosynthesis. Hydrogen isotopic fractionation has thus become a valuable tool in the elucidation of plant biosynthetic pathways (42,43). 

To understand the distribution and pathways of organic material in the ocean the key question is "What happens to that 99% of the phytoplankton biomass that is remineralized between photosynthesis and burial "... 

Studies (see, e.g., (101)) indicate that photosynthesis originated after the development of respiratory electron transfer pathways (99, 143). The photosynthetic reaction center, in this scenario, would have been created in order to enhance the efficiency of the already existing electron transport chains, that is, by adding a light-driven cycle around the cytochrome be complex. The Rieske protein as the key subunit in cytochrome be complexes would in this picture have contributed the first iron-sulfur center involved in photosynthetic mechanisms (since on the basis of the present data, it seems likely to us that the first photosynthetic RC resembled RCII, i.e., was devoid of iron—sulfur clusters). 

Carbon isotope discrimination by leaves with the C3 pathway of photosynthesis is related to pj/pa (Farquhar et al., 1982), through... 

An intriguing stress-induced alteration in gene expression occurs in a succulent plant, Mesembryanthemum crystallinum, which switches its primary photosynthetic CO2 fixation pathway from C3 type to CAM (Crassulacean acid metabolism) type upon salt or drought stress (Winter, 1974 Chapter 8). Ostrem et al. (1987) have shown that the pathway switching involves an increase in the level of mRNA encoding phosphoenol-pyruvate carboxylase, a key enzyme in CAM photosynthesis. 

Colorless, reactive gas. Oxygen was not present in the initial atmosphere of the Earth, although at 50 % it is the most common element in the crust of the Earth (oxides, silicates, carbonates, etc.). The compound with hydrogen is remarkable. The hydrides of all other elements are unpleasant compounds, but H20 is the molecule of life. The 02 found in the air today, of which it makes up 20 %, was formed in the process of evolution by photosynthesis of algae, which then also allowed life on solid land. Oxidation with oxygen became and is still the dominant pathway of life forms for obtaining energy (respiration). Used in medicine in critical situations. Oxidations play a key role in chemistry (sulfuric acid, nitric acid, acetic acid, ethylene oxide, etc.). The ozone layer in space protects the Earth from cosmic UV radiation. Ozone (03) is used in the... 

The outcome of the photosynthesis processes is ultimately similar in all green plants carbon dioxide from the atmosphere is taken up by the plants, where it reacts with water to form carbohydrates and oxygen the carbohydrates are assimilated by the plants while the oxygen is released to the atmosphere (see Textbox 53). Extensive studies have shown that the conversion of carbon dioxide and water into carbohydrates in different plants may follow, however, one of three different photosynthetic pathways, which are usually referred to as the C3, C4, and CAM paths. Each type of plant follows just one of these three pathways. 

O.G. Poluektov, L.M. Utschig, A.A. Dubinskij and M. Thurnauer, ENDOR of spin-correlated radical pairs in photosynthesis at high magnetic field A tool for mapping electron transfer pathways, J. Am. Chem. Soc., 2004, 126, 1644. 

Another important area is the use of photochemistry—chemistry that results from light absorption—to perform transformations that are not otherwise possible. The practical applications of photosynthesis were based on fundamental work to learn the new pathways that light absorption makes possible, but the work on these synthetic methods has also added to our basic understanding of the reaction mechanisms. The important natural process of photosynthesis also inspires some work in photochemistry, where the challenge is one of producing artificial photosynthetic systems that could use sunlight to drive the formation of energetic materials. 

The pathway of electron flow is called the Z scheme of photosynthesis because the diagram from p680 to p700 resembles the letter Z (Figure 7.10) [37,39]. 

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