Biologically, there are four general types of macromolecules or biomolecules. They are carbohydrates, proteins, lipids and nucleic acids. Each of these plays an important role in maintaining life among living creatures and each is a piece of the elaborate puzzle of metabolism. Each has a different chemical composition and interacts with other molecules differently. Most of these biomolecules come from food sources and we are therefore already familiar with them. Without a proper balance of all four of these molecules, however, an organism will surely be affected, sometimes negatively. Carbohydrates are used as an immediate energy source by nearly all living organisms (Mader, 2010). The majority of carbohydrates have a carbon to hydrogen to oxygen ratio of 1:2:1 and they include single sugar molecules as well as chains of sugar molecules. Monosaccharides are what we consider to be ready and available energy. They consist of only one single sugar molecule. A simple sugar can have a carbon backbone of three to seven carbons. Glucose, with six carbon atoms, is a hexose (Mader, 2010). Ribose and deoxyribose, both with five carbon atoms, are pentoses and are also found in RNA and DNA. A disaccharide contains two monosaccharides that have joined together during a dehydration reaction. Sucrose is a disaccharide of distinction because it’s the basic sugar we use at home as table sugar (Mader, 2010). Lactose is the disaccharide found in milk and dairy products. Polysaccharides are polymers of monosaccharides. Some of these function as short term energy sources. When an organism requires energy, the polysaccharide is broken down to release two sugar molecules (Mader, 2010). Plants store glucose in starch in the form of amylase and amylopectin. Animals store glucose as glycogen which is stored in the human liver and released under control of certain hormones. Lipids are another macromolecule that we commonly refer to as fats.
Cited: 1.) Mader, Sylvia S. (2010). Biology 10th Ed. (pp. 2-7). New York: McGraw-Hill.