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Leaf chromatography. A LSS ACE project (Term 3) by Edward Tan 1A3 (23). Procedures. 1. Collect different types of leaves and vegetables. 2. Cut the coffee filter papers (or chromatography paper) into strips. 3. Use PENCIL to draw a line 2 cm above the bottom tip of the filter paper.
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Leaf chromatography A LSS ACE project (Term 3) by Edward Tan 1A3 (23)
Procedures • 1. Collect different types of leaves and vegetables. • 2. Cut the coffee filter papers (or chromatography paper) into strips. • 3. Use PENCIL to draw a line 2 cm above the bottom tip of the filter paper. • 4. Use a coin, scratch the pigment from the leaves and vegetables onto the filter paper ( must be near the line drawn). • 5. Fill a small container with rubbing alcohol.
Procedures • 6. Gently place the filter papers into the container of rubbing alcohol. ( note: only the filter paper’s tip should touch the alcohol.) • 7. After several minutes, changes should be observed. Wait for a while, then remove the filter papers out of the container.
Materials Diff. types of leaves Filter Paper A coin
Use a coin to scratch the different leaves onto different strips of filter paper.
The four different strips of filter paper for the different leaves
Getting ready for the dipping of the strips of filter paper into the alcohol
Observations • The alcohol moves up the paper strips and the pigments also move up the paper. • Yellow and slight traces of green pigments can be seen in the yellow and green leaves, while it is not observable in the red cabbage leaf. • Red and purplish pigments are seen in the red cabbage leaf.
Explanation/ Conclusion • As alcohol moves up the filter paper, the pigment dissolves. Because of the different characteristics of the pigments in the leaf, some pigments move faster than the others. • Different colourleaves have different pigments, thus we can see different chromatography for the four different leaves. • Leaves contain pigments that give them colour: Chlorophyll, Carotenoids and Anthocyanin. • Chlorophyll carries a green pigmentation. • Carotenoids carry yellow, orange and brown pigments. • Anthocyaninscarry red and purple pigments.
Explanation / Conclusion • All leaves have chlorophyll but chlorophyll are constantly been used up in the photosynthesis process. It is possible that only very slight traces of green are observed in the yellow and green leaves because chlorophyll is not replaced when the leaves are detached from the trees and plant. • Carotenoid pigment is often found in chloroplast and aids in the process of photosynthesis. This yellow pigment is readily seen in the chromatography. • Red cabbage has the same pigments as the green, with additional anthocyanin. Perhaps the difference is that anthocyanin concentrations in red cabbage are much greater. Hence we cannot really observe the yellow and green colours.