Living organisms processes

Biological reactions in vivo rarely operate under conditions even remotely approaching those of reversibility. For a living organism, the rate of a process is usually more important than the attainment of equilibrium, and large driving... 

The ability of living organisms to differentiate between the chemically similar sodium and potassium ions must depend upon some difference between these two ions in aqueous solution. Essentially, this difference is one of size of the hydrated ions, which in turn means a difference in the force of electrostatic (coulombic) attraction between the hydrated cation and a negatively-charged site in the cell membrane thus a site may be able to accept the smaller ion Na (aq) and reject the larger K (aq). This same mechanism of selectivity operates in other ion-selection processes, notably in ion-exchange resins. 

Porphyrins and chlorophylls are the most widespread natural pigments. They are associated with the energy-converting processes of respiration and photosynthesis in living organisms, and the synthesis of specific porphyrin derivatives is often motivated by the desire to perform similar processes in the test tube. The structurally and biosynthetically related corrins (e.g. vitamin B,j) catalyze alkylations and rearrangements of carbon skeletons via organocobalt intermediates. The biosyntheses of these chromophores are also of topical interest. 

Vimses are obligate intracellular parasites. They only exhibit activity by infecting other living organisms, thus they are not a practical concern in industrial microbiological fields. The exception is where viral contamination of the product or process represents a threat of transmission of disease. Microscopic insects and protozoans are also not addressed in this article (see Insectcontroltechnology). 

Bacteria Living organisms, microscopic in size, which usually consist of a single cell. Most bacteria use organic matter for their food and produce waste products as a result of their life processes. 

Biotechnology- Use of living organisms to carry out defined physiochemical processes having industrial or other practical application. 

Biotechnology Commercial processes dial use living organisms, or substances from diose organisms, to make or modify a product. This includes techniques used for improving die characteristics of economically important plants and animals and for die development of microorganisms to act on die environment. 

Very little is known about the occurrence of 1-hydroxytryptamine and/or 1-hydroxytryptophan derivatives in living organisms. Many 1-methoxyindole derivatives have been isolated as natural products (87MI629, 88BCJ285, 92H1877, 93MI22) for the simple reason that they are stable under isolating processes. 

In living organisms, a similar process occurs, although a tliioester or acyl adenosyl phosphate is the substrate rather than a carboxylic acid chloride. 

The most common example of this process in living organisms is the reaction of the amino acid methionine with adenosine triphosphate (ATP Section 5.8) to give S-adenosylmethionine. The reaction is somewhat unusual in that the biological leaving group in this SN2 process is the triphosphate ion rather than the more frequently seen rliphosphate ion (Section 11.6). 

Many processes in living organisms are closely linked to energy transfer and to charge transfer complexes. Therefore, studies of the properties of PCSs are important in solving certain problems of bioenergetics, enzymatic catalysis, photoinduced carcinogenesis, etc. 

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