Lesson 2 - Complex Carbohydrates and Demonstration
Student Performance Objectives1. List and define 2 examples of complex carbohydrates. 2. Describe 2 locations in the body where complex carbohydrates are important.3. Describe an experiment to demonstrate the breakdown of starch to maltose by saliva.Lesson OutlineA. Complex carbohydrates 1. Glycoproteins: combinations of carbohydrate and protein. E.g., mucus 2. Glycolipids: combinations of carbohydrate and lipid. 3. The glycocalyx located at the surface of cells is a combination of glycoproteins and glycolipids and acts as a surface recognition region: immune system determines "self from nonself" at this area. 4. Proteoglycans: mostly carbohydrate and some protein complexed together to form the gel that helps to hold cells and tissues together and helps to form the synovial fluid that lubricates the joints. Discuss the thixotropic nature of synovial fluid (i.e., multiple-viscosity liquid).B. DEMONSTRATION (or Student Activity): The various simple tests for the major types of macromolecules are performed. Reducing sugars like glucose or maltose are tested using Clinitest tablets or Fehling's solution with observation of the color change (blue to greenish to brick red) after the exergonic reaction. Starch is tested using Lugol's iodine and observation of the blue-black color of the starch-iodine complex. The slippery nature of saliva is noted, compared with water, based on the content of the glycoprotein, mucus.