MACROMOLECULES

 ORGANIC COMPOUNDS: molecules that contain carbon and hydrogen. In addition to these two elements, biological molecules may also contain O, P, N and S. Living cells make and use a variety of organic molecules.  The following are the four major classes of biological macromolecules: Carbohydrates, Lipids, Proteins and Nucleic acids.  Macromolecules are polymers, very large molecules composed of smaller subunits (monomers; “building blocks”).

 CARBOHYDRATES: composed of carbon, hydrogen and oxygen in the proportion of 1:2:1.  They are commonly known as sugars.  Carbohydrates are the most important sources of energy for living organisms, providing both short and long term energy storage.  We get carbohydrates from the plants in our diet.  The names of most carbohydrates end with “ose”.

MONOSACCHARIDES or SIMPLE SUGARS:  Glucose: found in blood and in all the cells of your body. It is your primary source of energy.

 Fructose: found in fruits and honey. It makes an ideal sugar for many diet foods because it tastes much sweeter than glucose.  Galactose: found in milk, brain, nerve and cell walls.  Ribose/ Deoxyribose: found in nucleic acids

DISACCHARIDES or DOUBLE SUGARS  A process called DEHYDRATION SYNTHESIS (aka CONDENSATION) forms all disaccharides from two monosaccharides.  Building larger molecules from smaller ones is called ANABOLISM.  Common disaccharides are:  Maltose: a malt sugar found in beer, germinating seeds, and starch. It is made by  Glucose + Glucose  Maltose + Water

 Sucrose: found in sugar cane, and sugar beet. It is made by:  Glucose + Fructose  Sucrose + Water  Lactose: found in milk. It is made by:  Glucose + Galactose  Lactose + Water

POLYSACCHARIDES  Large, molecules composed of many simple sugars linked together.  Common Polysaccharides are:  Starch: found in plants (wheat, potatoes, etc.) Many glucose molecules are inked into and form starch.  Cellulose: a component of plant cell walls It is also a long chain of glucose but the glucose molecules are linked in a different way than in starch.  Glycogen: form of carbohydrate storage in animals (stored in the liver and muscles). It is a branched chain of glucose.