In: Biology
DISCUSSION:
1. The green areas in the leaf contains what pigment?
2. Why do you use hot water to extract the red pigments?
3. Why do you use alcohol to extract chlorophyll?
4. What is the purpose of iodine in this experiment?
5. Blue/purple areas in the leaf after iodine was added contained
what molecule? ____________
6. Are the blue/purple areas found where the green sites used to
be? ________________
7. What does this result imply regarding chlorophyll function in a
plant leaf?
1. Chlorophyll
2. Water is a solvent for the coloured pigments. In air or oil, the same pigments are less or even not at all soluble. Hot water can damage cells. Proteins, which give structure to cells and membranes, denature at hot temperatures and thus red coloured pigment becomes soluble in hot water.
3. Alcohol is used to remove chlorophyll because it brakes the outer membrane of the leaf. Chlorophyll can be easily dissolved in organic solvents such as ethanol.
4. Iodine is an indicator of the presence of starch. It turns blue-black in the presence of starch.
5. Starch
6. Starch granules have been visualized in the stroma of the chloroplast as well as the cytoplasm.
7. Chlorophyll in the leaves is responsible for photosynthesis which is a process by which green leaves prepare the food in the form of carbohydrates and which is stored in the form of starch with the help of sunlight, co2 and water.