1. Lab 4 1-(Prove the importance of chlorophyll in photosynthesis). 2-Prove the production of starch during the process of photosynthesis 3-Prove the activity of Catalase enzyme in plant tissues.

2. photosynthesis What is photosynthesis ? Photosynthesis is the process by which Plants use the energy from sunlight to Produce sugar. The conversion of sunlight energy into chemical energy is associated with the Actions of the green pigment Chlorophyll. 6H₂O + 6CO₂ C₆H₁₂O₆ + 6O₂

5. Prove the importance of chlorophyll in photosynthesis Tools and subjects : Glass Beaker, alcohol,iodine solution, green leaves

6. Method : 1-Draw the leaf after it was disposed to enough sunlight showing in the draw the green spots and white spots. 2-Dip the leaf in boiling water for a minute to kill all the cells. 3- Dip the leaf in alcohol until all the chlorophyll is gone. 4- Lmmerse the leaf in iodine solution and compare the color with draw.

7. Result: Comparing the immersed leaf iodine with the first draw we find that only The green spots were colored in blue.

8. Comment: The spots that colored in blue indicates that there was starch during photosynthesis Because its cells have chlorophyll, but the white spots that haven’t got chlorophyll can Not perform photosynthesis so it didn’t colored in blue but colored with the color of iodine and that prove the importance of chlorophyll in photosynthesis.

9. Prove the production of starch during the process of photosynthesis Tools and Materials : Glass Beaker, alcohol, iodine solution, green leaves

10. Method: 1- Take a green fresh leaf that has exposed enough to sunlight. 2- Dip the leaf in boiling water for a minute to kill all the cells. 3- Dip the leaf in alcohol to absorb chlorophyll until the green color Disappears from the leaf. 4- lmmerse the leaf in iodine solution and observe the color. Result: The leaf color turned blue. Comment: The green cells perform photosynthesis that results in the production of starch which colored Blue when dipped in iodine solution.

11. Prove the activity of Catalase enzyme in plant tissues Tools and Materials: Test tubes, potato cubes,hydrogen peroxide H₂O₂. Mode of action of catalase enzyme : Catalase presents in plant tissues and with high amounts in potato Its activity can be detected by catalyze the conversion of hydrogen :peroxide into water and oxygen as follows Method: 1-Place potato cubes in a test tube 2-Add 1 ml hydrogen peroxide and close the tube and shake it. 3-Remove the stopper and after 1-2 min and observe the rise of bubbles oxygen H₂O₂ CATALAS H₂O+O₂

13. Result: The rise of oxygen bubbles in the test tube proves the activity of catalase enzyme in plant tissues.