Lab 4 Energy and Photosynthesis BIO101L
Energy and Photosynthesis
Pre-Lab Questions
- Describe how the functional units for beta carotene, xanthophyll, chlorophyll A, and chlorophyll B are different. Be sure to identify the subunits that adhere to paper during chromatography.
- Describe a technique for measuring photosynthetic rate.
- Many deciduous trees have leaves which turn yellow in the fall. What do you suppose is happening in the leaves at the cellular and molecular level?
- Chloroplasts and mitochondria are both are unusual in that they have double membranes and contain their own set of DNA. Can you think of any explanations for this observation?
Experiment 1: Paper Chromatography
Table 1: Part 1: Chromatography Data
| Solvent | Distance from Original Line to Solvent Font | Number of Bands | Rf Factor |
| Acetic Acid | |||
| Acetone | |||
| Mineral Oil | |||
| Water | |||
Table 2: Part 3: DPIP Photosynthesis Data
| Test Tube | Chloroplast Solution Present? | Initial Color | Final Color | Time Required to Change Color (Hours) |
| 1 | ||||
| 2 | ||||
| 3 |
Post-Lab Questions
- What did the different colored bands signify in each solvent for Part 1? What pigments can you associate them with?
- What is the osmolarity fluid used in Part 2? Why is this important? Why is it essential to keep it cool?
- How could you modify this experiment to show the effects of different wavelengths of light on the photosynthetic rate?
- Some plants (grasses) tend to contain a greater concentration of chlorophyll than others (pines). Can you develop a hypothesis to explain this? Would it be testable?
- Insert a picture of the four pieces of chromatography paper with your name clearly and access code handwritten in the background. (Part 1)
- Insert a picture of the final color of the solutions in their test tubes with your name and access code handwritten in the background. (Part 3)
Cassey
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