Download Name

Name: ___________________________________________________ Date: ___________ Block: __________
Separation of Leaf Pigment
Introduction:
Photosynthesis begins when light is absorbed by pigments in the plant cell. One technique for
separating and identifying these pigments is paper chromatography. In paper chromatography, solvent moves
up the paper carrying with it dissolved substances – in this case, plant pigments. The pigments are carried along
at different rates because they are not equally soluble in the solvent and are attracted in different degrees to the
paper.
In this investigation, you will use paper chromatography to determine what color pigments exist in a
spinach leaf by observing different colored bands on the paper.
What pigment(s) do you expect to see in the spinach leaf chromatography? ____________________________
Materials:
Spinach leaf
wooden stick
beaker with isopropyl alcohol
chromatography paper
coin
Procedure:
1. Carefully take your piece of chromatography paper
and set it on the table.
Do not touch the paper with your fingers. Use a ruler
to make a pencil line
across the bottom of the strip of paper approximately
1.5 cm from the bottom.
2. Lay the piece of spinach over the pencil line. Roll
your coin across
the line at least 5 times to grind the leaf pigments
onto the paper.
You should see a dark green line on your paper.
3. Use a piece of tape to carefully attach
the paper to your wooden stick.
4. Hang the paper in the beaker at your
table. Be sure only the bottom
of the paper is in the solution in the cup.
5. Wait 30 minutes and remove your paper
from the cup and lay on the table to dry
a little.
6. Use your ruler to underline all of the
different colors or shades of color that you can see and make a list of the colors. Measure how far each
of the colors moved from the original green line in centimeters.
Band
Color
Distance traveled from base line (cm)
1
2
Analysis Questions:
1. Write out the formula for photosynthesis. Label the molecules.
__________________________________________________________________________________________
2. What is the green pigment in plants that absorbs light? ___________________________________________
3. In which cell part is this pigment located? _____________________________________________________
4. List 2 differences between ADP and ATP. _____________________________________________________
__________________________________________________________________________________________
__________________________________________________________________________________________
5. What gas do plants give off as a result of photosynthesis? _________________________________________
6. What gas do plants take in for photosynthesis? _________________________________________________
7. Plants go through photosynthesis to make what? ________________________________________________
8. How many different colors did you find on your chromatography paper? _____________________________
9. If the other pigments absorb light at different wavelengths than chlorophyll, why do you think it is good for
the plant to have pigments in addition to chlorophyll? ______________________________________________
__________________________________________________________________________________________
__________________________________________________________________________________________