Water carbohydrate structure

Cellulose and starch are macromolecules with empirical formulas that resemble hydrated carbon, CX (H2 0)y, where x and y are integers. The monomers from which these macromolecules are consfructed are sugars such as glucose and fructose. These monomers and macromolecules are the carbohydrates. Structurally, carbohydrates are very different from simple combinations of carbon and water. Even the smallest carbohydrates contain carbon chains with hydrogen atoms, OH groups, and occasional ether linkages. 

Antipova, A.S., Semenova, M.G. (1997a). Effect of neutral carbohydrate structure in the set glucose / sucrose / maltodextrin / dextran on protein surface activity at the air-water interface. Food Hydrocolloids, 11, 71-77. 

Antipova, A., Semenova, M., Gauthier-Jacques, A. (1997). Effect of neutral carbohydrate structure on protein surface activity at air-water and oil-water interfaces. In Dickinson, E., Bergenstahl, B. (Eds). Food Colloids Proteins, Lipids and Polysaccharides, Cambridge, UK Royal Society of Chemistry, pp. 245-258. 

From the observation that N-(mcLhylcnc)morpholinium cations (17) induced the autocatalytic decomposition of tertiary amine W-oxides in combination with the proof that these intermediates were actually present in Lyocell dopes, the question arose why Lyocell solutions were stable at all. The answer is found in the fact that carbenium-iminium ions generated are immediately consumed by reaction with water and carbohydrate structures as the most abundant and most reactive nucleophiles present. Only when the local concentration of 17 increases to such a high level that the consumption by reaction with water or cellulose cannot compensate for its production, does the reaction with NMMO become uncontrollable and lead to an exothermic event. The pulp used in the Lyocell process acts as a quasi-stabilizer for the solvent NMMO, albeit with the drawback of increased chromophore generation. 

In the carbohydrates, the water molecules most commonly have fourfold, nearly tetrahedral coordinations, which function as crossing-points for infinite or finite chains, thereby forming network structures. In this sense, the inclusion of water molecules in carbohydrate structures makes the hydrogen bonding more ice-like. 

Meng, Y. and Rao, M. A. 2005. Rheological and structural properties of cold-water-swelling and heated cross-linked waxy maize starch dispersions prepared in apple juice and water. Carbohydrate Polymers 60 291-300. 

Glycosaminoglycans and proteoglycans form a water-rich protein-carbohydrate structure that absorbs compressions stresses in the extracellular matrix. 

Besides the monosaccharides, there are more complicated carbohydrate structures such as disaccharides and polysaccharides. These may be regarded as being formed as a result of a reaction in which a molecule of water is eliminated between two hydroxyl groups (a type of reaction known as a condensation reaction) ... 

Montforts et further explored this approach by attaching hydrophilic carbohydrate structural units to certain chlorins (e.g., 406). Such conjugation increased the water solubility of the parent chlorins 407 and 408. By introducing an estradiol with a diethyl spacer, the chlorin-estrogen conjugate was then prepared in the hope that it would bind to an estrogen receptor which could induce selective destruction of mammalian carcinoma (Scheme 82). 

To illustrate how important carbohydrates are to life itself, sunlight is essential to all life, and plants convert carbon dioxide (CO2) to carbohydrates in the presence of water and sunlight (photosynthesis). Carbohydrates store energy within living systems, and this process is required for life. For all animals, including humans, their very essence is carried in the DNA found in genes, and DNA is simply a polymeric sugar with heteroaromatic substituents. This chapter will introduce carbohydrate structure, nomenclature, preparation, and reaction. 

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