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Why Do Leaves Change Color?. Extracting Pigments From Chloroplasts. Materials. Leaf Small clear paper cup Alcohol to fill cup approx. ½ full Paper towel Coffee filter Plastic fork or knife. Procedure. Flatten filter and place it on paper towel.
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Why Do Leaves Change Color? Extracting Pigments From Chloroplasts
Materials • Leaf • Small clear paper cup • Alcohol to fill cup approx. ½ full • Paper towel • Coffee filter • Plastic fork or knife
Procedure • Flatten filter and place it on paper towel. • Using the blunt side of the knife or the fork handle, gently rub the leaf against the edge of the filter. Green chlorophyll will begin to appear on the filter. Continue until you have a good amount of green. • Cut from sides of green to middle of filter. • Place cut strip into alcohol-filled cup.
Procedure (cont.) • Allow the filter/chlorophyll to set in the alcohol for at least one hour. • Remove from the alcohol and observe what happened.
Results • The chlorophyll should have quickly turned the alcohol green. • After approx. 30 minutes, hidden pigments should have begun to appear. • You might see red, brown, or yellow. Colors vary, depending upon which pigments are in the particular left you are working with.
Why Does This Happen? • The green chloroplasts mask the other pigments. They are always there. We just can’t see them until cool weather approaches and photosynthesis decreases. Without food production, the green disappears and the masked pigments appear. Eventually the leaf falls.