Not all the light energy from the sun is absorbed. Sunlight has many different colors in it. Chlorophyll usually absorbs red and blue light from the sun and reflects green light. It's the green light reflecting that makes some leaves look green! The leaf on the left is a variegated leaf. The green parts contain chlorophyll and photosynthesise to make starch. The white part of the leaf does not contain chlorophyll, so does not photosynthesise.
The leaf on the right shows a positive test for starch in the areas which contained chlorophyll, and a negative test for starch in the areas which lack chlorophyll. This is evidence that chlorophyll is required for photosynthesis. Parts of its leaves are covered with dark paper, and the plant is left in the light for a few hours. A lot of our understanding about starch initiation and formation in leaves has come from work on the model plant Arabidopsis thaliana. However, there is still a lot of work to do to understand granule initiation and formation within cereal grains.
As cereals are one of the major food crops, and a major source of starch for industrial processes, understanding granule initiation and formation in grains is crucial. At the John Innes Centre we are using a large mutant collection of wheat to investigate the granule initiation and have already isolated several promising mutants with radically altered starch granules. By investigating these further, we hope to identify key candidates involved in granule initiation in wheat, which may allow the development of new tools to improve crop quality and tailor starch production properties for different uses.
Professor Cathie Martin is to give two special lectures after being elected to be the Janaki Ammal Visiting Professor by the Indian Academy of Sciences for , as an outstanding woman in science. Try the test again with a variegated leaf one with both green and white that has been in the sunlight. A leaf needs chlorophyll to perform photosynthesis — based on that information, where on the variegated leaf do you think you would find starch?
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Find affordable beakers, test tubes, chemicals, kits, and everything else you need for lab experiments. Grade Range: Adaptable for Grades 3 - 8. Overview: Learn about food webs by dissecting owl pellets. Erica Saint Clair explains how these five cool summer projects incorporate entertaining, hands-on science. To get started with our leaf chromatography experiment, we first must learn about leaves. Leaves contain different pigments, which give them their color.
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