Carbohydrate reaction summary

The purpose of the present article is to review comprehensively those photochemical reactions of carbohydrates for which product structures have been established, and to apply current mechanistic reasoning to the understanding of these reactions. Two reviews of carbohydrate photochemistry already exist. The first1 2 was published in this Series in 1963, prior to the considerable recent growth in this field, and the second was a brief summary published in the Japanese literature in 1973. 

A. C. Richardson, Nucleophilic replacement reactions of sulphonates, Part VI. A summary of steric and polar factors, Carbohydr. Res., 10 (1969) 395 4 02. 

In summary, the strength of wood panels tested here did not hold up when the urea/carbohydrate molar ratio was lowered to 0.125 1, but did not suffer drastically when the caustic components of the adhesive were reduced by a third. Glycosyl ureides were the only intermediates identified in the sequence of reactions leading from monosaccharide to polymer, because of the quickly-escalating multiplicity of products. 

In many papers the term "superoxide" (HOO ) is used simultaneously with "superoxide anion radicals" (Oa )- However, this is under the physiological conditions incorrect The pKa value of this acid-base equilibrium is 4.8 [227] and, therefore, there is only a very small contribution of HOO at physiological pH (7.4). Therefore, the term "superoxide anion radical" should be exclusively used. The superoxide anion radical is both, a one-electron oxidant and a one-electron reductant. The reactions of O2 with many different biological substrates were studied in detail by the radiation chemists and a summary of the obtained second order rate constants is provided in [228]. However, not a single carbohydrate is mentioned in this comprehensive survey since no reaction could have been observed [229]. 

A summary of the hydrolysis reactions of carbohydrates, proteins, and fats. 

Iii this chapter on the hydrazine derivatives of sugars and related compounds, an attempt has been made to offer more than a review of what has already been achieved by focusing on reactions that have not yet been tried on carbohydrate substrates (examples of these are given in Sections III.3 and IV.4). In summary, a serious effort has been made to point to novel approaches for the synthesis of, and new applications for, the reactions of saccharide hydrazones and their carbocyclic analogs. 

The citric acid cycle, also known as the tricarboxylic acid cycle or the Krebs cycle, is the final oxidative pathway for carbohydrates, lipids, and amino acids. It is also a source of precursors for biosynthesis. The authors begin Chapter 17 with a detailed discussion of the reaction mechanisms of the pyruvate dehydrogenase complex, followed by a description of the reactions of the citric acid cycle. This description includes details of mechanism and stereospecificity of some of the reactions, and homologies of the enzymes to other proteins. In the following sections, they describe the stoichiometry of the pathway including the energy yield (ATP and GTP) and then describe control mechanisms. They conclude the chapter with a summary of the biosynthetic roles of the citric acid cycle and its relationship to the glyoxylate cycle found in bacteria and plants. 

The last four chapters of the text complete our study of the molecular basis of life. This chapter and the next three build on your knowledge of the biomolecules (carbohydrates, lipids, proteins, and nucleic acids) and examine the processes that support living organisms. Your attention should now be directed toward gaining an understanding of these processes, where they occur in the cell, their purpose, and, in some cases, key summary reactions. 

Summary of Reactions of Carbohydrates 1019 [ WHY DO THESE TOPICS MATTER ] 1020... 

Richardson, A. C. Nucleophilic Replacement Reactions of Sulphonates. Part VI. A Summary of Steric and Polar Factors. Carbohydr. Res. 10, 395 (1969). 

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