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The green color of leaves throughout spring and summer comes from chlorophyll, a pigment vital to photosynthesis. As we get closer to autumn and some parts of the planet get fewer hours of sunlight, trees respond by stopping the food-making photosynthesis process and slowing the production of chlorophyll until, eventually, they stop producing it altogether and the green color of the leaf fades. Yellow and Orange: Along with chlorophyll, there are yellow and orange pigments, carotene and xanthophyll, inside some trees’ leaves. For most of the year, these pigments are masked by chlorophyll, but as the chlorophyll breaks down and the green color dissipates, the yellow to orange colors become visible.
Red: Another class of pigment that occurs in leaves is the anthocyanins. Anthocyanins, unlike carotene and xanthophyll, are not present in leaves year-round. It isn’t until the chlorophyll begins breaking down that the plant begins to synthesize anthocyanin. Why do trees begin producing a different pigment in leaves they’re getting ready to lose? The prevailing theory is that anthocyanins protect leaves from sun damage, lower their freezing point, allow them to remain on the tree longer, and buy the tree more time to recover nutrients from its leaves. The colors that anthocyanins produce are dependent on the pH of the leaves’ cell sap. Very acidic sap results in a bright red color, while less acidic sap leads to a purplish red. Read the full text here: http://www.mentalfloss.com/blogs/archives/34223#ixzz29gLMgHU1 --brought to you by mental_floss! Today we went on a field trip to Olive school to see what it was like in 1776 the first person is Angus McClain he's a militia. The second lady is Christina Johnson the news maker. The third person is Kathrine Caird the school mistress. I did not know it takes so much trading to get food,weapon's, and even just wigs. Did you know all men wear wigs that are made from real human hair? That's gross!!! They even pull teeth. You wanna know who pulls the teeth? THE WIG MAKER!!!! Now that's weird. I would not like to go to school back then because if you got something wrong you would get wacked with a wooden stick. In school you have to learn in a barn or a tent that would be really distracting.
Today at science class, we did an expirement about insulators. All of us were given partners and we were told to use any materials we could bring in to keep a bottle full of hot water hot in an ice bath. The layers we put on our bottle had to fit inside a gallon sized plastic bag. I thought it was an almost impossible task! My partner brought some materials from home and we used some of the stuff Mr. Solarz had kindly set out for our use. Of course, he bought everything from garage sales. Anyway, our insulators did a fair job. The top temp on the above graph did not change much, indicating that we had kept the bottle warm. We could have stuffed the bag full of materials like scraps of paper and felt like some groups did. Although we didn't do that, we did the steps right.
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AuthorWrite something about yourself. No need to be fancy, just an overview. Archives
May 2013
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