Chromatography Of Chlorophyll Lab Pre-ap

Chromatography of Chlorophyll Paper chromatography is a useful way to separate out the different pigment molecules in chlorophyll. Using a solvent, pigments found in plants are separated. The pigments are able to dissolve in the solvent and separate from each other. When they separate, the different colors of the pigments will be visible. This way we can tell which pigments are inside the leaves. The pigments will be absorbed along a paper column until they reach the top. Larger pigment molecules will move up the paper slower and , smaller pigment molecules will move up the paper faster. Procedure: 1. 2. 3. 4. 5. 6. 7. 8.

Obtain a strip of chromatography paper. Measure 1 inch from the bottom and mark a pencil mark ( MUST BE PENCIL) Obtain a piece of a leaf wider than the strip of paper Using a coin, roll the coin across the pencil mark smooshing the chlorophyll from the leaf on the pencil line. Now, the line should be heavily covered in green chlorophyll. Very carefully place the strip into the jar containing the solvent. Be careful not to get the line in the liquid solvent! Cover the jar. Let the jar sit undisturbed until the liquid has moved up to very near the top of the strip of paper. (DON’T let the liquid run off the strip!)

9. Attach the strip to the paper here: Label the different color pigments as; COLOR REFLECTED

Dark green to blueish-green Yellowish green to (olive) Orange- yellow Lemon yellow

PIGMENT NAME chlorophyll a chlorophyll b carotene xanthophyll

Answer the questions:

1. Which pigment moved the farthest up the paper? ____________________ 2. Which pigment moved the shortest distance up the paper? _______________ 3. If the largest molecule moved the slowest and the smallest molecule moved the fastest up the paper, then name the molecules in order from largest to smallest Largest _____________________________ ______________________________ ______________________________ Smallest ______________________________ 4. In the autumn, when the leaves change color, what pigments become weaker in expression? ______________________ and _________________________ 5. In the autumn, which pigments become more DOMINANT? __________________________________________________