Biological Macromolecules Lab
Biological Macromolecules Lab
Cells, the fundamental units of life, are composed of various combinations of organic macromolecules: carbohydrates, lipids, proteins, and nucleic acids. This lab exercise is designed to show you the qualitative tests commonly used to detect their presence.
Objectives
Test for the presence of monosaccharides by using the Benedict’s test
Test for the presence of starch, a polysaccharide, by using the Lugol’s iodine test
Test for the presence of lipids by using the Sudan test
Test for the presence of proteins by using the Biuret reagent test
Determine the identity of an unknown substance by detecting the presence of organic macromolecules using the above tests
Introduction
Biological macromolecules are defined as large molecules made up of smaller organic molecules. There are four classes of macromolecules: carbohydrates, lipids, proteins, and nucleic acids. The base elements of carbohydrates and lipids are carbon (C), hydrogen (H), and oxygen (O). Proteins are also made up of these base elements but it also contains nitrogen (N).
Carbohydrates have the general formula [CH2O]n (where n is the number of repeating units). The main function of carbohydrates is short-term energy storage (such as glucose). A secondary function is intermediate-term energy storage (as in starch for plants and glycogen for animals). In addition, some carbohydrates are involved as structural components in cells, such as cellulose in the cell walls of plants and chitin in the exoskeleton of arthropods.
Sugars are structurally the simplest carbohydrates. They are the structural units which make up the other classes of carbohydrates. Monosaccharides are single (mono) sugars. Important monosaccharides include ribose (C5H10O5), glucose (C6H12O6), and fructose (an isomer of glucose). Disaccharides are formed when two monosaccharides are chemically bonded together. Monosaccharides are lniked into disaccharides and polysaccharides by a reaction that requires
Cells, the fundamental units of life, are composed of various combinations of organic macromolecules: carbohydrates, lipids, proteins, and nucleic acids. This lab exercise is designed to show you the qualitative tests commonly used to detect their presence.
Objectives
Test for the presence of monosaccharides by using the Benedict’s test
Test for the presence of starch, a polysaccharide, by using the Lugol’s iodine test
Test for the presence of lipids by using the Sudan test
Test for the presence of proteins by using the Biuret reagent test
Determine the identity of an unknown substance by detecting the presence of organic macromolecules using the above tests
Introduction
Biological macromolecules are defined as large molecules made up of smaller organic molecules. There are four classes of macromolecules: carbohydrates, lipids, proteins, and nucleic acids. The base elements of carbohydrates and lipids are carbon (C), hydrogen (H), and oxygen (O). Proteins are also made up of these base elements but it also contains nitrogen (N).
Carbohydrates have the general formula [CH2O]n (where n is the number of repeating units). The main function of carbohydrates is short-term energy storage (such as glucose). A secondary function is intermediate-term energy storage (as in starch for plants and glycogen for animals). In addition, some carbohydrates are involved as structural components in cells, such as cellulose in the cell walls of plants and chitin in the exoskeleton of arthropods.
Sugars are structurally the simplest carbohydrates. They are the structural units which make up the other classes of carbohydrates. Monosaccharides are single (mono) sugars. Important monosaccharides include ribose (C5H10O5), glucose (C6H12O6), and fructose (an isomer of glucose). Disaccharides are formed when two monosaccharides are chemically bonded together. Monosaccharides are lniked into disaccharides and polysaccharides by a reaction that requires