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Polymers and Crystals Background Info.
Monosaccharides are sugars in their simplest form. They are carbohydrate molecules which serve as
building blocks for the more complex carbohydrates. Dietary monosaccharides include:
Glucose (sometimes called dextrose, grape sugar, and corn sugar) is the most prevalent
monosaccharide. It is found in fruits, vegetables, honey, corn syrup, and molasses. It is a structural unit
of all common dietary disaccharides and the basis for all polysaccharides.
Fructose (sometimes called levulose) is the second molecule used for sucrose. It is the sweetest of all
the sugars and is found in honey, molasses, fruits, and vegetables.
Galactose does not occur in a free form in foods but is produced when lactose or milk sugar is digested,
or when milk products are fermented.
Disaccharides contain two units of monosaccharide. Sucrose, more commonly known as table
or regular sugar, is the most common one used. Sucrose is extracted from either beet or cane sugar.
Sucrose is the crystalline form resulting when one molecule of glucose and one molecule of fructose
combine to form sucrose and water. The chemical formula for producing sucrose illustrates how this
formation of sugar takes place. (Glucose and fructose have the same chemical formula but differ in
molecular structure.)
glucose + fructose = sucrose + water
C6H1206 + C6H1206 = C12H22011 + H20
The body uses sugar by reversing this process. It is called the hydrolysis of sugar. Lactose is
hydrolyzed in the body by an enzyme lactase which breaks down the lactose into two monosaccharideglucose and galactose. The galactose is then further broken down in the liver to form glucose. Glucose
is used by the body for energy.
Polysaccharides or Polymers contain many molecules of monosaccharide. The main ones are:
Starch is the most abundant dietary carbohydrate and is reduced to sugar by digestive processes.
Dextrin are short glucose chains formed from starch.
Cellulose is the unique structural component used primarily by plants. Human bodies cannot digest
cellulose.
Poly means many. Mer means parts. Polymer means many parts. Polymers are long chains of
molecules. Polymers have a carbon nucleus with hydrogen cross bonded to them.
Man -Made Polymers

Plastic

Nylon

Grease
Natural Polymers

Cotton

Wool

Hair

Skin

Protein

Gelatin

Polysaccharides
Pure sugars (sucrose) are solid at room temperature and will liquefy or decompose when
heated. The melting point is about 320 F (160 C). At that temperature, it forms a colorless liquid. With
continued heating, it becomes yellow, and with additional heat, the color change progresses to brown and
then to nearly black. This process is known as caramelization. It is a chemical process. Care must be
taken not to let the process go too far otherwise a bitter, burnt flavor develops. Caramelized sugars can
be used in many ways especially to produce color.
Sugar has gained a poor reputation in that too much of it will be stored in the body for
emergency purposes. Some people will gain weight; develop diabetes, heart, or other diseases; or have
poor teeth as a result of an improper sugar balance.
Sugar plays an important role in food preparation. It has several functions in food preparation and in the
body:
1.
Used by the body for energy.
2.
Enhances food flavors.
3.
Promotes tenderness, fine texture, greater volume, and browning in baked products.
4.
Stabilizes egg white foam.
5.
Increases tenderness of starch-thickened gels, gelatin products, and egg dishes.
6.
Promotes production of carbon dioxide by yeast.
7.
Acts as a dehydrating agent in pectin gel formation.
8.
Lowers the freezing point of mixtures (ice cream).
9.
Increases the boiling point of mixtures (candy).
Sugar crops up as an added ingredient in such unlikely places as (among others) soda
crackers, spaghetti sauce, soups, salad dressing, ketchup, table salts, and many medicines. Sugar also
comes in many disguises. For example, the following (among others) are forms of sugar: honey, syrup,
corn sugar, corn syrup, molasses, invert sugar, brown sugar, sucrose, fructose, glucose, dextrose,
maltose, and lactose.
Sugar tastes good to most people. Bacteria that cause tooth decay love it too. When exposed
to sugar, especially sucrose, the bacteria in the mouth thrive on it and form an acid that weakens tooth
structure and forms decay.