Laboratory Module 8. Plant Physiology (2):
Plant Pigment Paper Chromatography
All organisms need energy for their metabolic processes. They also need “food” to produce that energy. Plants are autotrophs (self-feeders). Plants produce their food through a process called Photosynthesis. The food that they produce is the sugar glucose. Animals and other organisms are heterotrophs (other- feeders). They must consume other organisms (plants) in order to eventually get their glucose. Both plants and animals use glucose as an input to the process of Cellular Respiration (another subject) to produce ATP molecules. ATP molecules are the energy source for all metabolic processes.
Log on to the following web site for a good explanation of photosynthesis. Pay attention to the part that discusses chlorophyll and accessory pigments.
http://www.emc.maricopa.edu/faculty/farabee/biobk/biobookps.html
Paper Chromatography
The process of photosynthesis utilizes pigments to absorb light to energize the procedure. Through the process of paper chromatography you can separate these pigments to demonstrate a partial step in the photosynthesis process.
Log on to the following web site for an explanation of how these pigments are separated.
http://jchemed.chem.wisc.edu/JCESoft/web/cplsample/Modules/paprchrom/paprchromdesc.htm
Plants contain pigment molecules that are the center of the plants ability to make energy and food from sunlight (photosynthesis). The main pigments are chlorophylls (green), but other pigments of different colors assist in light absorption. This lab allows you to discover what these pigments are and their properties.
Materials: • A large bag of spinach leaves. • Alcohol Solvent: rubbing alcohol (isopropanol) or grain/everclear (ethanol). • Coffee filters. • Blender, Juicer or Food Processor • Small to medium glass jars