Joie Li
Dr. Marble B2 AP Biology
AP Investigation #5: Cell Processes: Photosynthesis
November 24, 2014

Part 1:

Part 2:
Assessment Questions (Parts 1 and 2)
1. The Carotene pigment (light yellow) migrated the farthest on the chromatogram. The migration of the pigments occurred through rubbing a line of spinach with the side of a coin onto chromatography paper, then soaking the paper with 1 mL of chromatography solvent in a vial to allow absorption. The order of lines (absorption) was Carotene, Xanthophyll, Chlorophyll A and Chlorophyll B. Carotene’s color allowed it to travel the highest, and the same statement applies to the other colors.
2. Rf stands for the ratio between distance traveled by component from point of application to distance traveled by solvent from point of application. Since it relates to the distance traveled according to the length of the paper, and assuming that measuring would occur when the solvent was about 1 mm from the end of the sheet, the Rf values would be similar.
3. Since plants absorb red and blue colors on the spectrum and reflect green (that’s why we see it as green with the naked eye) the unabsorbed wavelengths are seen in the spectrum.
4. The rate of photosynthesis will be affected by the intensity of the light, the solvent the discs are placed in (water, salt or soap), the size of the photosynthesizing area and the plant that it was tested on.
5. If light were to be removed from the setup after the discs floated to the surface, I predict that they would sink down again. The discs initially rose because of respiration that was happening inside of them due to the water and light that, through photosynthesis, created O2 air, which caused them to float. But once the light had been taken away, chloroplasts can no longer produce O2 and the discs sink once again.

Part 3 Open Inquiry
1. If the spinach discs in bicarbonate are placed in colder temperature water, then the time needed for them to float up will increase.
2. Based on previous experiments, the time needed for the discs to float up was longer in bicarbonate was longer than the time in plain water. Since we know the solvent of the discs are in affects the rate, we want to test if temperature will with both a control of the same number of discs in plain room temperature water and room temperature bicarbonate.
3. Controls: 13 spinach discs in both plain water cups and bicarbonate
Variables: 13 spinach discs in bicarbonate cup in beaker filled with ice water
Observations: Discs in bicarbonate cup in ice water never floated up
4. The most plausible result would be that the cup with colder temperature’s floatation rate would be slower due to the incorrect temperatures needed for photosynthesis and the production of O2 gas.
5. Materials: Sodium bicarbonate solution, plastic