2. Carbohydrates Definition : are macromolecules, consists of Carbon, Hydrogen and Oxygen. H and O are found in same proportion as in water (H2O). Biological Significance of Carbohydrates: 1- Carbohydrates are the major source of Energy. 2- Stores energy in form of glycogen in liver and muscles. 3- Component of cellular membranes (as well as organelles membranes). e.g. cellulose of plant cell wall, and Actin for cuticle of insects outer bodies.

3. Types of Carbohydrate in living organisms : can be divided into 3 types 1-Monosaccharides: The simplest form of carbohydrates. Monosaccharide exists in form of (unbranched )chain, or in cyclic form (ring). Molecular formula is (CH 2 O)n, where n is number of C atoms and =3,4,5,6,7. Monosaccharides are classified by the number of carbon atoms: Trios (3 carbon atoms), tetrose(4), pentose (5), hexose(6), heptose(7). The cyclic (ring) form can be either a pentose (5) or hexose (6) only. e.g. Glyceraldehyde (Triose)( C3H6O3), Ribose and deoxyribose (pentose) found in nucleic acids. Glucose and fructose (hexoses).

4. 2-Disaccharides: Formed by binding of 2 units of monosaccharides by glycosidic bond (-O-). Molecular formula is C 12 H 22 O 11. * Maltose: 2 units of glucose, Joined together by glycosidic bond. * Sucrose: Glucose + fructose,Sucrose is table sugar we use as sweetener for food and drinks. * Lactose: Galactose + glucose, it is milk sugar.

5. 3-Poly saccharides: Large molecules composed of repeating units of monosaccharides. Molecular formula is (C 6 H 10 O 5 )n, where n = number of monosaccharides units. A-Polysaccharides can be divided chemically to:1- Homo-polysaccharides: consists of one type of monosaccharides. 2- Hetero-polysaccharides: consists of different types of monosaccharides, e.g. Hemicellulose ( present along with cellulose in almost all plant cell walls.) - Hyaluronic acid.( is a substance that is naturally present in the human body )cellulosecell walls B- Polysaccharides can be divided according to function to:

6. ObjectReagents and dyes (For read) FeaturesSlide Glycogen (Animal Starch)  periodic acid Schiff (PAS) method Tissue parts stained red indicate presence of glycogen Nutritional Polysaccharides Glycogen in liver Mucoid Substance (polysacch aride derivatives )  Alcian blue method Tissue parts stained blue indicate presence of Mucoid substances. Mucus in mucus gland المواد المخاطية في الأمعاء mucus in intestine Starch Gieson Stain Starch granules stained dark. Nutritional Polysaccharides Starch granules in potatoe.

8. Observation: Sucrose solution with Fehling’s: Red brown precipitant Sucrose solution with Silvanof: Bright red color Results

9. 2-Effect of Invertase enzyme on Sucrose Digestion and Hydolysis: 1- Prepare invertase enzyme extract by grinding 10 gm of yeast with 5 ml distilled water and table sugar. 2- In test tube, put 2 ml of sucrose solution (2%) + 2 ml of Fehling reagent (1ml of Fehling A and 1 ml of B), heat in 37˚C water bath for 6 min. 3- In new test tube, put 2 ml of sucrose solution + 2 ml of invertase extract and mix well. Then put in for 15 min. Add 2 ml of Fehling reagent (A & B), heat in boiling water bath for 10 min. Results