Lab 20: Energy and Photosynthesis pre lab and post lab

Experiment 1: Paper Chromatography

Data Tables and Post-Lab Assessment

Table 1: Part 1: Chromatography Data

Solvent	Distance from Original Line to Solvent Front	Number of Bands	Rf Factor
Acetic Acid
Acetone
Mineral Oil
Water

Table 2: Part 3: Photosynthesis Data

Test Tube	Time Required to Change Color	Initial Color	Final Color	Time Required to Change Color (Hours)
1
2
3

Post-Lab Questions

1. What did the different colored bands signify in each solvent for Part 1? What pigments can you associate them with?

2. What is the osmolarity fluid used in Part 2? Why is this important? Why is it essential to keep it cool?

3. How could you modify this experiment to show the effects of different wavelengths of light on the photosynthetic rate?

4. 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?

5. Saliva does not contain amylase until babies are two months old. How could this affect an infant’s digestive requirements?

Answer the following 5 questions in depth:

1. What was the main theme of this experiment?
2. To what degree were the objectives outlined in the introduction to this experiment met?
3. What conclusions were drawn from the results?
4. What was the clearest and also the most difficult aspects of this experiment?
5. How would you improve this experiment?

Lab 20: Energy and Photosynthesis

Pre-Lab Questions

1. 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.

2. Describe a technique for measuring photosynthetic rate.

3. 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?

4. 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?