Carbohydrate usual

Nucleoside (Section 28 2) The combination of a purine or pynmidme base and a carbohydrate usually ribose or 2 deoxynbose... 

The elemental and vitamin compositions of some representative yeasts are Hsted in Table 1. The principal carbon and energy sources for yeasts are carbohydrates (usually sugars), alcohols, and organic acids, as weU as a few other specific hydrocarbons. Nitrogen is usually suppHed as ammonia, urea, amino acids or oligopeptides. The main essential mineral elements are phosphoms (suppHed as phosphoric acid), and potassium, with smaller amounts of magnesium and trace amounts of copper, zinc, and iron. These requirements are characteristic of all yeasts. The vitamin requirements, however, differ among species. Eor laboratory and many industrial cultures, a commercial yeast extract contains all the required nutrients (see also Mineral nutrients). 

Because carbohydrates usually have numerous chirality centers, it was recognized long ago that a quick method for representing carbohydrate stereochemistry is needed. In 1891, Emil Fischer suggested a method based on the projection of a tetrahedral carbon atom onto a flat surface. These Fischer projections were soon adopted and are now a standard means of representing stereochemistry at chirality centers, particularly in carbohydrate chemistry. 

The primary energy source in PN solutions is carbohydrate, usually as dextrose monohydrate. Available concentrations range from 5% to 70%. When oxidized, 1 g of hydrated dextrose provides 3.4 kcal. 

Caramel in this context means a brown colour that is produced either traditionally by heating sugar or as a very intense product that is made by heating carbohydrate, usually glucose syrup, with ammonia. Caramel colour is the product of the Maillard reaction, i.e. the reaction of a reducing sugar with an amino group. Chemically the colour is a melanoidin - these substances are extremely stable and can be used in any type of confectionery. 

Assay methods are available for most of the carbohydrates ranging from glycogen, starch, and cellulose to the monosaccharides and their monophosphates. Concentration determination of complex carbohydrates usually depends on their enzymatic hydrolysis to monosaccharides and determination of monosaccharide concentration via an enzymatic reaction. For example, starch is hydrolyzed to glucose by glucoamylase, and the... 

These proteins are composed of simple proteins in combination with carbohydrates like mucopolysaccharides, which include hyaluronic acid and chondroitin sulphates. On hydrolysis, mucopolysaccharides yield more than 4% of amino-sugars, hexosamine and uronic acid e.g., ovomucoid from egg white. Soluble mucoproteins are neither readily denatured by heat nor easily precipitated by common protein precipitants like trichloroacetic acid or picric acid. The term glycoproteins is restricted to those proteins that contain small amounts of carbohydrate usually less than 4% hexosamine. 

Following recent advances in antibody engineering, it is now possible to s)mthesize humanized antibodies [35]. Because of clinical applicability, antibody-based medicines are one of the biopharmaceutical categories that have attracted close attention in recent years [36]. IgG has been most frequently used for the prevention and treatment of various diseases. The CH2 region of IgG has A-linked carbohydrates (usually complex type double stranded chains) in diverse manners (O Scheme 14). It has recently been revealed that differences in the carbohydrate structure affect the effecter activity of antibodies such as antibody-dependent cellular cytotoxicity (ADCC) and their half-life in blood, inviting close attention from the viewpoint of improving the responses to antibody-based medicines [37,38,39]. 

Aldehydes and ketones react with alcohols by acid-initiated nucleophilic addition to form hemiacetals which are usually unstable. Reaction with a second mole of alcohol produces a acetal. Carbohydrates usually exist in hemiacetal or acetal forms. 

The nomenclature of carbohydrates usually includes the suffix -ose. Monosaccharides may also be identified according to the nature of the carbonyl functional group (aldose or ketose), the number of carbons in the molecule (tri-, tetr-, pent- ose) or a combination of these two. Monosaccharides also have common names such as ribose, glucose, galactose, and fructose (four of the most common monosaccharides found in nature). 

Glycolipids are another type of sphingolipid. Unlike sphingomyelins, however, these complex lipids contain carbohydrates (usually monosaccharides such as glucose or galactose). Glycolipids are often called cerebrosides because of their abundance in brain tissue. The structure of a typical cerebroside is... 

---