Carbohydrates
Carbohydrates are cosmopolitan in nature within the sort of sugars, starches, celluloses, and other complex substances.
Carbohydrates are the collective name of polyhydroxyaldehydes and polyhydrooxyketones.
These compounds form a serious class of biomolecules the perform several functions storage and transport of energy.
Carbohydrates are a serious source of energy in our diet.
The empirical of carbohydrates is Cn(H2O)n.
They provide 4 kcal in 1 gram of carbohydrates and promote the use of fats and reduce wastage of proteins.
Cereal grains provide the foremost economic source of food carbohydrates. due to their high-carbohydrate and low-water content, cereals are easy to grow, harvest, store, transport, and process. Ideally, carbohydrates should supply 60 to 70 percent of total calories required.
Carbohydrates are usually classified into three types, monosaccharides, oligosaccharides, and polysaccharides.
Nomenclature and structure
The basic unit of carbohydrates is termed a monosaccharide.
Two monosaccharides that join together are called disaccharides and three are called trisaccharides.
. Oligosaccharides contain two to 10 monosaccharide units joined in glycoside linkage.
Polysaccharides contain many monosaccharide units, from hundreds to a couple of thousand, joined in linear or branched chains. Most polysaccharides contain recurring monosaccharide units of just one kind or two alternating kinds.
Carbohydrates were first named consistent with the sources from which they were obtained, e.g., dextrose , cane sugar, maltose , lactose , corn starch and liver glycogen. Then they were named from a prefix associated with the sources followed by the suffix—"ose", e.g., fructose (fruit sugar), maltose (malt sugar), lactose (milk sugar), xylose (wood sugar), and cellulose (carbohydrates from cell membranes).
Monosaccharides
Monosaccharides are simple sugars containing short chains of carbon atoms with one aldehyde or ketone group (carbonyl group), each of the remaining carbon atoms carry a hydroxyl.
Aldehyde group are called "aldoses" (names ending in—"ose") and people with a group are referred to as "ketoses" (names ending with—"ulose").
Depending upon the entire number of carbon atoms present within the monosaccharide molecule, they're designated as trioses (3 C-atoms), tetroses (4 C-atoms), pentoses (5 C-atoms), hexoses (6 C-atoms) then on
The simplest sugars are glyceraldehyde and dihydroxyacetone.
The most greater monosaccharide is the 6-carbon sugar, glucose (dextrose).
. it's also the essential building block of the foremost abundant polysaccharides— starch and cellulose.
Oligosaccharides
Oligosaccharides are formed by the polymerization of n molecules of monosaccharides by the elimination of n-l molecules of water.
The most significant sort of oligosaccharides occurring in food are disaccharides ,which are formed by the condensation of two monosaccharide units to make a glycosidic bond.
Disaccharides are often homogeneous and heterogeneous.
Non -Reducing Sugar
Non -Reducing sugar during which the monosaccharides unit are joined by a glycosidic bond formed between their reducing group.
When water is eliminated between anomeric hydroxyls of various units, non-reducing oligosaccharides, like sucrose, raffinose, etc., are formed.
Reducing sugar
Reducing sugar during which the monosaccharides unit are joined by a glycosidic bond formed between their reducing group of 1 monosaccharide to the second monosaccharides unit .
They often build oligosaccharides in foods such as sucrose, maltose, lactose, raffinose, and stachyose
Polysaccharides
Polysaccharides are built of the repeat units of monosacchararides.
They are formed by a couple of sorts of hexoses, hexose derivatives (uronic acids and sulphate esters) and pentoses.
They are high-molecular-weight substances composed of an outsized number of monosaccharide units combined to make one large molecule or polymer.
The generic name of polysaccharides is "glycans."
They contains a primary chain and, in some, side chains or branches may exist. the first chain consists usually of 1 , but sometimes two, sorts of monosaccharide units. The side chains may contains sugars different from those of the most chain, with differing types of glycosidic linkages. Polysaccharides commonly found in foods such as starch, dextrins, glycogen(C6H10O5)n cellulose, hemicellulose, pentosans, and pectic substances
If they're composed of one sort of monosaccharide unit they're homoglycans, and if of two or more monosaccharide units, they're heteroglycans. Glycans that free only glucose on hydrolysis are glucans (hexosan) and xylose, xylans (pentosan)..
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