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Leaf Chromatography

Last updated over 3 years ago
8 questions
Welcome to class! Please complete the following.

1. In the back of the classroom, have 1 person collect your leaves and chromatography paper. Bring them to the front circlular table.
2. Grab a paper towel and lay all 4 filter papers out on the table. Place your 4 chromatography papers on the paper towel.
3. Throw out your leaves and dump the alcohol down the drain.
4. Rinse out the beakers and place them upside down next to the sink to dry.
1

Draw a sketch of what all four your 4 chromatrography papers look like. Use color, labels, and be sure to draw the banding in the correct locations. Label which side was dipped in the alcohol.

Read the text below:

Photosynthesis is the process in which plants convert light energy from the sun to chemical food energy.  To absorb the light, leaves use brightly colored  pigments with chlorophyll being the most important one.

There are two main types of chlorophyll: chlorophyll A which is bluish-green, and chlorophyll B, which is yellowish-green. During most of the growing season, leaves contain more chlorophyll than any other pigment, making them appear green.
In the fall, chlorophyll begins to break down, and the other pigments, which have been there all along, are finally revealed.  Yellow leaves have pigments called xanthophyll, orange leaves have a pigment called carotenoids. Anthocyanins give leaves their intense red and purple pigments.

These pigments, however, aren’t present in the leaves during the summer and are only made toward the end of summer.
Chromatography is the separation of a dissolved mixture by passing a  through filter paper through which different parts of the mixture will move at different rates.  The pigments that were more soluble in the solvent (alcohol) moved further up the paper than the less soluble pigments.  Using the green leaf as an example, the blueish-green chlorophyll A was less soluble than the yellowish green chlorophyll B and thus it didn’t move as far up the paper.
1

What is photosynthesis?

1

Why do leaves change color in the fall?

1

Which colored pigments traveled furthest on your chromatography paper?

1

Why did some colors travel further than others?

1

Of the 4 leaf colors, what type of pigment are you observing in each?

1

What is your favorite thing about fall?

1

What is your favorite season?

Complete any make up work that you have that is still available!