1. Photosynthesis
Lab # 7
Biology 201
Fall 2017

2. Photosynthesis

4. 2 reactions summary
Light reactions: (use chlorophyll)  ATP + NADPH + O2
Dark reactions: CO H  PGAL
PGAL ---- glucose, sucrose, fructose, maltose, starch, and cellulose

5. Exercise A: light requirements of photosynthesis
Pieces of light screening papers were placed on leaves to prevent photosynthesis and plant was exposed to light.
The leaves were boiled in alcohol and soaked in Iodine.
Iodine is an indicator for starch. The spots covered by the paper should not show a reaction, since no photosynthesis.

6. Exercise B: pigment localization and photosynthesis
Coleus plants contain three pigments; green chlorophyll, red anthocyanin, and light yellow carotenoid.
Aim 1, remove a leaf and sketch it!
Aim 2, boil the leave in water to determine which pigment is water soluble! Do a second sketch!
Aim 2, boil in alcohol to remove all pigments. Place leave in Iodine to test for starch! Is there a correlation between pigment localization and photosynthesis? Do a third sketch.

7. Exercise F: Separation of pigments by paper chromatography

8. Stationary phase- water molecules bound to the chromatography paper
Mobile phase- the moving solvent (10% benzene and 90% petroleum ether)
Solutes- the pigments in the pigment mixture
2 forces account for results!
Driving force- the solvent carrying the pigments to the end of paper
Resistance force- the dissolution of each solute in the cellulose associated paper.

9. Follow the procedure in your book to set up the chromatography!
Please mark the starting line with a pencil!
Let it run 15 minutes.
Mark the solvent front with a pencil!

10. The pigments you should get are
Orange yellow (carotene)
Gray (anthocyanin)
Yellow (xanthophyll)
blue-green (chlorophyll A)
Yellow green (chlorophyll B)

11. Determine the Rf value for your pigments!
Rf value= distance traveled by individual pigment/ distance traveled by solvent.
Example; chlorophyll A = 4/12
= 0.33

12. Complete the chart on page 67
Complete pages and submit next week!