I. Identifying the Effects of Different Variables of Light and Carbon Dioxide on the Rate of
Photosynthesis and Observing the Separation of Pigments Through Chromatography
Plants have a variety of pigments, all of which absorb a different color of light. The three main pigments are chlorophyll a, chlorophyll b and carotenoids. Chlorophyll a is the primary plant pigment that absorbs red and blue light, which ultimately appears green to the human eye because green light is reflected instead of being absorbed. Chlorophyll b and carotenoids both function to capture light energy and transfer it to the reaction center located in chlorophyll a. Part
A of this lab involves the experimentation of chromatography to separate spinach pigments. …show more content…
4. Which trial worked best? Explain.
A: The trial with carbon dioxide and a light source 30cm away worked best. This is because the light source for this variable was the closest to the plant out of all the trials, which means that the plant is receiving the most light in order to perform photosynthesis at a more optimal rate.
5. What was the purpose of using the water/soap solution for one of the trials?
A: The soap causes the membrane in plant cells to open and allow free exchange of oxygen and carbon dioxide. This solution served as the control for this experiment.
6. What is the effect of darkness on photosynthesis?
A: Darkness significantly slows the rate of photosynthesis. Without light, photosynthesis cannot occur as photosynthesis requires light as a reactant for the process to occur.
7. If we were to boil the leaf disks, what kind of results would you expect? Explain.
A: Photosynthesis would not occur since the molecules would be denatured, disallowing the functionality of the molecules to react with one another. There would also be no space for gases to move in and out, forcing the leaf disks to stay at the bottom of the