Lesson 2 - Complex Carbohydrates and Demonstration

Student Performance Objectives
1. 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 Outline
A. 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.