IB Macromolecule Model Building
Macromolecules make up a large group of organic compounds found in cells. They are generally used for energy, structure and support, signal recognition, pumps, and other functions. Generally they consist of atoms of carbon, hydrogen,oxygen, and nitrogen.
With this lab exercise you will construct three groups of carbohydrates (monosaccharides, disaccharides and polysaccharides) and a lipid. You will also be able to distinguish differences in molecular and structural formulas.
Single Sugars or Monosaccharides:
The model constructed represents the three-dimensional shape of the molecules. They illustrate that individual molecules of carbohydrates do differ from one another in general structural shape even though their molecular formulas are the same. They also will illustrate how it is possible for molecules to join together to form different carbohydrates. Have your model checked by instructor.
Two monosaccharide molecules can chemically join together to form a large carbohydrate molecule called a double sugar, or disaccharide. When a glucose molecule chemically joins with another glucose molecule, a double sugar known as maltose is formed. When a glucose molecule joins with a fructose molecule, a different double sugar called sucrose is produced (There are no questions for this section).
Just as double sugars were formed from two monosaccharide molecules, complex sugars are formed when many single sugars are joining together chemically. The exact number of glucose molecules attached to form these polysaccharides is not known. The two most common polysaccharides in biology are starch and cellulose. They consist of long chains of glucose molecules joined together.
Lipids are a group of carbon compounds that are insoluble in water (can’t be broken down by water). Triglycerides are one of the primary groups of lipids and include adipose tissue in humans and oil in sunflower seeds. Triglycerides are produced by the combination of three fatty acid tails and one glycerol molecule through dehydration synthesis. Fatty acids can be saturated, monounsaturated or polyunsaturated.