What Are Monosaccharides

The word carbohydrate means hydrate of carbon and derives from the formula CnCHgO),. Two examples of carbohydrates with molecular formulas that can be written alternatively as hydrates of carbon are 

Not aU carbohydrates, however, have this general formula. Some contain too few oxygen atoms to fit the formula, whereas some contain too many. Some also contain nitrogen. But the term carbohydrate has become firmly rooted in chemical nomenclature and, although not completely accurate, it persists as the name for this class of compounds. 

At the molecular level, most carbohydrates are polyhydroxyaldehydes, polyhydroxy-ketones, or compounds that yield them after hydrolysis. Therefore, the chemistry of carbohydrates is essentially the chemistry of hydroxyl and carbonyl groups and of acetal bonds (Section 12.6A) formed between these two functional groups. 

Monosaccharides have the general formula C H2 0 , with one of the carbons being the carbonyl group of either an aldehyde or a ketone. The most common monosaccharides have from three to nine carbon atoms. The suffix indicates that a molecule is a carbohydrate, and the prefixes trir, tetr-, pent-, and so forth, indicate the number of carbon atoms in the chain. Monosaccharides containing an aldehyde group are classified as aldoses those containing a ketone group are classified as ketoses. 

There are only two trioses—glyceraldehyde, which is an aldotriose, and dihydroxyac-etone, which is a ketotriose  

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What are monosaccharides Disaccharides Polysaccharides Give examples. 

What are the products of oxidation and reduction of the monosaccharides Mucic add, of which the preparation from d-galactose has been described, is optically inactive and incapable of resolution, just like duldtol, the corresponding hexahydric alcohol. As the formula shows, the four asymmetric carbon atoms of galactose form two pairs (2, 5 and 3, 4) having the same substituents but opposite arrangement in space, and when the carbon atoms 1 and 6 become alike, inactive forms are produced by intramolecular compensation, as in mesotartaric acid. 

Show an equation for a ICiliani-Fischer synthesis starting from D-ribose. What are the names of the monosaccharides produced in this reaction ... 

Question What are two ways in which a monosaccharide in a ring form, like glucose, differs from cyclohexane in conformation ... 

Polysaccharides are naturally occurring polymers, which can be considered as derived from aldoses or ketoses by condensation polymerization. A polysaccharide derived from hexoses, for example, has the general formula (C6H]oOs)n. This formula, of course, tells us very little about the structure of the polysaccharide. We need to know what the monosaccharide units are and how many there are in each molecule how they are joined to each other and whether the huge molecules thus formed are straight-chained or branched, looped or coiled. 

What are the main oxidizing agents used to oxidize monosaccharides to carbonic acids ... 

What are the functional groups that exist in monosaccharides ... 

When D-tagatose is added to a basic aqueous solution, an equilibrium mixture of three monosaccharides is obtained. What are these monosaccharides ... 

What are carbohydrates, and what are the monomers in carbohydrates The monosaccharides in Table 22.8 are all optically active. Explain. What is a disaccharide Which monosaccharide units make up the disaccharide sucrose What do you call the bond that forms between the monosaccharide units What forces are responsible for the solubility of starch in water What is the difference between starch, cellulose, and glycogen ... 

What are some oxidation-reduction reactions of sugars Monosaccharides can undergo various reactions. Oxidation reactions make up one important group. 

Answer the following questions regarding raffinose (a) What are the monosaccharides obtained upon hydrolysis (b) Identify linkages A and B. (c) Is raffinose a reducing sugar ... 

What are the structural differences among monosaccharides, disaccharides, and polysaccharides ... 

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