Polypeptides organic acids

The Databases menu provides tools for building polypeptides (Amino Acids, Make Zwitterion, Sequence Editor), polynucleotides (Nucleic Acids), polysaccharides (Saccharides), and organic polymers (Polymers) from residues (monomer units) as exemplified for DNA in Figure 14.11. 

Chemists have devoted much effort to exploring this natural world of chemistry as well as to determining structures the natural world has stimulated the extension of the chemical world into models and analogs of the natural chemicals. The field of organic chemistry was influenced heavily by the types of chemical structures found in natural products many medicinal compounds are still invented by using natural products as models for analogs. Chemists have also invented important polymers once nature showed us the natural polymeric carbohydrates, polypeptides, nucleic acids, and the polymers such as rubber that are produced from natural materials. 

Seawater also contains a wide variety of dissolved organic compounds, the total amount being about 2 ppm. More than 100 different compounds have been identified in solution in seawater. These include a wide variety of organic acids, carbohydrates, amino acids, polypeptides, as well as various vitamins. 

Silica gel Alcohols, aldehydes, alkaloids, amines, amino acids, amphetamines, antibiotics, antioxidants, barbiturates, carbohydrates, flavonoids, herbicides, heterocyclic compounds, hydrocarbons, indoles, insecticides, ketones, lipids, nitro compounds, organic acids, peroxides, pesticides, phenols, plasticizers, polypeptides, steroids, terpenes, unsaturated compounds, vitamins. 

Other Variables. The effect of the polypeptide molecular weight upon a has not yet been conclusively established for any polypeptide-organic solvent system. Recent extensive studies of the charge-induced transition of polyglutamic acid in aqueous solution have shown an increase in a with a reduction in molecular weight 15). Similarly the influence of polypeptide solute concentration is not yet clear, though Ackermann and Riiterjans 1) have demonstrated a remarkably large effect of this variable upon AH0 in PBG. Neither of these points is discussed further in the present paper. 

Complexing and chelate forming of toxic ions are possible to prevent their direct contact with sensitive enzymes. For Ah, the complexes with organic acids are important within the plant (Ma et al. 1997, Wenzel et al. 2002). In other instances, proteins or phytochelatins (polypeptides consisting of repetitive glutamylcys-teine units) are formed which bind the toxic ion. While the role of an additional synthesized protein in Al-tolerant wheat genotypes merits further consideration (Taylor et al. 1997), the detoxification of Cd (Tukendorf and Rauser 1990) by phytochelatins is evident. 

In this chapter, we summarize and discuss articles published during the last 10 years in which conformational energies of various classes of organic molecules computed by a number of different molecular mechanics methods have been compared to each other and to experimental data. This review focuses entirely on force fields developed for ordinary organic compounds. Force fields specialized for only polypeptides, nucleic acids, or carbohydrates are not included. 

Some of the substances that have been separated by this method are given in papers referred to by Morris and Morris (1964) amino acids, peptides (particularly those having molecular weights ranging from 500 to 5000), polypeptide antibiotics, proteins (including enzymes), carbohydrates (although for most compounds in this chemical class other fractionation methods are much more frequently applied), purines, pyrimidines, nucleic acid derivatives, tRNA s that are specific for various amino acids, organic acids, steroids, lipids, antibiotics that are not peptides, porphyrins, pterins, vitamin B,2 and other vitamins, lipoic acid, and alkaloids. The countercurrent-distribution procedure of Holley et al. (1965) is widely used, sometimes with modifications. Korte et al. (1965) have separated three isomers of tetrahydrocannabinol. 

The dixnensioiis of the polypeptide chain and of its associated N—H O hydrogen bonds can be inferred with confidence. Data from many sources—X ray diffraction anal rseB of crystals of organic acids amides peptides and related compounds polarized infra-red studies of crystals— together with fundcunental concepts of structural chemistry now provide a basis for satisfactory knowledge cmd understanding of the dimensions and configurations of the... 

Amines and organic acids form condensation polymers known as polyamides. Alcohols and organic acids form condensation polymers known as polyesters. Amino acids form polyamide polymers known as polypeptides. Long, straight-chain polypeptides are known as proteins. 

Other constituents reported in A. vera include other polysaccharides, polypeptides, steroids, chromones, lectins, organic acids, enzymes, amino acids, saponins, and minerals.Carboxypeptidase, a serine carboxypeptidase enzyme found in A. arbor-escens and other species of Aloe, is suggested to be a primary antithermic agent. 

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