Leaves and Light

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Leaves and Light

Postby stricklande » Sun Nov 25, 2012 12:54 pm

My class just completed the "Leaves and Light" experiment. We placed various colored transparencies on a houseplant, rotated it daily in our classroom, and uncovered the transparencies a week later. The leaves did not change after the week. Did we do something wrong? Was there supposed to be a change in the coloration of the leaves?
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Project Question: My class completed the "Leaves and Light" experiment by placing colored transparency sheets on a house plant for 1 week, rotating it daily, and then uncovering the transparency sheets. There was no change in any of the leaves. We were wondering why there had been no change.
Project Due Date: 11/28/2012
Project Status: I am finished with my experiment and analyzing the data

Re: Leaves and Light

Postby grace7177 » Mon Nov 26, 2012 1:52 am

Welcome to Science Buddies!

First, I recommend you to check off the following essential procedures for the experiment below.
- Did you use clear transparency film?
- Did you use permanent markers of various colors?
- Did you cover different parts of the plant with different sheaths (including black construction paper and transparent film painted in different marker colors) ?
- Did you place your houseplant in an area exposed to sunlight?

If you checked off everything above and the problem reoccurs, I suggest that you perform a different experiment that still explores plant pigments in relation to photosynthesis. For your reference, I linked a helpful outline of different project that is similar in concept to the "Leaves and Light" experiment.

What Color Are the Leaves Really Turning? http://www.sciencebuddies.org/science-f ... p032.shtml

Hope this helps and good luck!

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Project Question: Biochemistry
Project Due Date: Completed
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Re: Leaves and Light

Postby Megara7 » Sun Dec 30, 2012 1:01 pm

While Grace has already given you a great start, I just wanted to add a few things. The reason we see things as colored is that objects have pigments that absorb certain wavelengths. The color that we see is the combination of all of the wavelengths of light that are not absorbed, but instead reflected back to our eye. The Leaves and Light experiment includes some background information about the different pigments that plants use (chlorophyll a, chlorophyll b, and Carotenoids). Since most plants appear to be green, these pigments combined should absorb all other colors, which are then used in photosynthesis.

Light (energy) is used in plants to energize electrons to facilitate photosynthesis (to produce sugar). Contrary to popular belief, this sugar is not used only in the mitochondria to produce energy for the plant's metabolic processes (reactions which the plant carries out to survive). The sugar is also used for growth. For example, it can be used to create cellulose (another type of sugar) which is used in cell walls.

Therefore, depending on which color light was given to the houseplant, the plant should have either grown and thrived, or it should have started to die/look unhealthy.

Also, some houseplants a such as CAM (crassulaceans) and C4 plants (most grasses and grassy plants) have specific adaptations in their photosynthesis processes that allow them to survive in adverse situations. By this, I mean that they have adaptations that allow them to have a slow metabolism and growth rate if such environments were introduced to it. So, if you used either of these categories of plants, this might be why when different colored lights were given to the plant, no changes could be perceived.

I hope this helps!
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