Photosynthesis Lab

This week in AP Biology we did a lab on plant pigments and photosynthesis. In the first part of the lab you get a piece of chromatoraphy paper and rub a spinach leaf on top of it with a quarter, so the pigment of the spinach leaf will be on the paper. You then put the tip of the chromatography paper into an alcoholic solvent, so the pigments will travel up the paper. When the pigments are completely done traveling up the paper, you measure where each pigment ends ( carotene, chlorophyll a, chlorophyll b) and  you calculate Rf values by dividing the pigment with the solvent. In the second part of the lab you get a spinach leaf and use a hole puncher to punch holes in the leaf to make leaf discs. After that you put the leaf discs in a syringe. Once the leaf discs are in the syringe, you fill the syringe up with. When the leaf discs are in the syringe with the solution make sure to make the leafs sink to the bottom by vacuuming the air out. Once the leafs are sunk, you then put the leaf discs into a solution which is mixed with water and baking soda (which gives off carbon dioxide) and you put the the leaf discs under a light source and calculate how many float to the top every 30 seconds.