Chemistry of carbohydrates

Simple sugars, starches and cellulose are organic compounds that have the approximate formula C(H2O)n, which accounts for the name carbohydrate (or hydrate of carbon) that is usually applied to this group of compounds. They are not truly hydrates of carbon but are polyhydroxy (alcohol) compounds that contain an aldehyde or ketone functional group. These functional groups give the carbohydrates some of their chemical properties that will be studied in this lab.

Simple sugars are called monosaccharides (one sugar), or disaccharides (2 sugars). Some monosaccharides are glucose, fructose, galactose, and xylose. Note that xylose is a pentose and fructose is a ketose.

Two common disaccharides are sucrose (table sugar) and lactose (milk sugar); sucrose is a combination of glucose and fructose linked together by their anomeric carbons to produce a nonreducing sugar (it does not reduce Cu2+), whereas lactose is a combination of galactose and glucose linked together by a β-1,4-glycosidic bond to produce a reducing disaccharide. When many sugar molecules are linked together into a polymer, the resulting compound is called a polysaccharide. Starches and celluloses are polysaccharides. Amylose is a linear chain polymer of glucose, whereas amylopectin (a plant starch) and glycogen (an animal starch) , starches and cellulose are organic compounds that have the approximate formula C(H2O)n, which accounts for the name carbohydrate (or hydrate of carbon) that is usually applied to this group of compounds. They are not truly hydrates of carbon but are polyhydroxy (alcohol) compounds that contain an aldehyde or ketone functional group. These functional groups give the carbohydrates some of their chemical properties that will be studied in this lab.