the only reason they look green is because they chloroplasts (organelle) in the plant cells have many pigment like molecules called CHLOROPHYLL that help in photosynthesis.
In plants, there is mainly blue-green chlorophyll and yellow-green chlorophyll. and the combination of these is what gives the plant it's green colour.
when it starts to get cold out and sunlight reduces, the tree no longer had a need to keep all of that chlorophyll in the cells because a) there isn't really enough sun to carry on with photosynthesis and b) it's preparing to hibernate (the tree-equivalent of)
as the chlorophyll fades out, the other pigments are now visible to the eyes giving the leaf it's red or orange or whatever coulour. These pigments where always there, we just didn't see them because of the chlorophyll.
so you know about those chloroplasts and their continuous production of organic molecules important for plant survival during the spring summer seasons, but what about the winter? well, deciduous plants have an adaptation where they lose their leaves during the winter to concerve energy. It makes sense right? plants need 100% humidity in their leaves for photosyntesis to take place + winter time does not provide a very productive environment for effective photosynthesis. SO plants lose their leaves. THe change in color is actually an indication of the leaves losing their life. OH NO. ha. so this color change from the usual green (lively chlorophyll) to yellow or orange (bring xanthophyll or beta carotines) is indicative of loss in plant productivity. The tree will [im not to knowlegdeble on this part so bear with me] do something with the bud where the leaf is attatched to the twig .. i think add another layer of tissue, to seperate teh leaf from the plant so it doesnt recieve anymore precious water. the chlorplasts stop functioning, chlrophyll becomes scarce and these accesory pigments, xanthophyll and carotene shows up vividly, no longer 'hidden' from the potent chlorophyll.
to sum it all up.. to save the plant
the tree will then make buds during the winter for the next season when all the leaves fall.
Leaves have this stuff called chlorophyll, that reflects a certain wavelength of light more than the other wavelengths (that reflected wavelenght being green, which is why you usually see green plants). In the autumn, the chlorophyll breaks down, allowing the other substances in the leaf that reflect different wavelenghts (reds, yellows, browns) better to show.
That is a simple answer. If you want to get more into depth about it look up photosynthesis and plant cell microbiology.
Leaves have clorophyll. In the wintertime, the chloropyll production is suppressed; therefore, leaves go through color change based apon the seasons, which is also based upon the temperature change.
Leaves have a green color in the summertime when cholorophll metabolism is the greatest and they have a color change in the autum/winter months when the chlorophyll metabolism is the slowest.
There is a well explained answer from the following Wisteme site. It's a little bit long, but I think I explains the question in every details. Hope it helps and enjoy reading it.
let me guess homework problem... well it has to do with in the summer there is more liht being absorbed into the leaf so all the colors but green absorb (an object is the color of what it reflects) but then in fall less light gets into the leaf so diff. light is absorbed and reflected
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the only reason they look green is because they chloroplasts (organelle) in the plant cells have many pigment like molecules called CHLOROPHYLL that help in photosynthesis.
In plants, there is mainly blue-green chlorophyll and yellow-green chlorophyll. and the combination of these is what gives the plant it's green colour.
when it starts to get cold out and sunlight reduces, the tree no longer had a need to keep all of that chlorophyll in the cells because a) there isn't really enough sun to carry on with photosynthesis and b) it's preparing to hibernate (the tree-equivalent of)
as the chlorophyll fades out, the other pigments are now visible to the eyes giving the leaf it's red or orange or whatever coulour. These pigments where always there, we just didn't see them because of the chlorophyll.
okay!
so you know about those chloroplasts and their continuous production of organic molecules important for plant survival during the spring summer seasons, but what about the winter? well, deciduous plants have an adaptation where they lose their leaves during the winter to concerve energy. It makes sense right? plants need 100% humidity in their leaves for photosyntesis to take place + winter time does not provide a very productive environment for effective photosynthesis. SO plants lose their leaves. THe change in color is actually an indication of the leaves losing their life. OH NO. ha. so this color change from the usual green (lively chlorophyll) to yellow or orange (bring xanthophyll or beta carotines) is indicative of loss in plant productivity. The tree will [im not to knowlegdeble on this part so bear with me] do something with the bud where the leaf is attatched to the twig .. i think add another layer of tissue, to seperate teh leaf from the plant so it doesnt recieve anymore precious water. the chlorplasts stop functioning, chlrophyll becomes scarce and these accesory pigments, xanthophyll and carotene shows up vividly, no longer 'hidden' from the potent chlorophyll.
to sum it all up.. to save the plant
the tree will then make buds during the winter for the next season when all the leaves fall.
hope it satisfies your curiosity!
Leaves have this stuff called chlorophyll, that reflects a certain wavelength of light more than the other wavelengths (that reflected wavelenght being green, which is why you usually see green plants). In the autumn, the chlorophyll breaks down, allowing the other substances in the leaf that reflect different wavelenghts (reds, yellows, browns) better to show.
That is a simple answer. If you want to get more into depth about it look up photosynthesis and plant cell microbiology.
Leaves have clorophyll. In the wintertime, the chloropyll production is suppressed; therefore, leaves go through color change based apon the seasons, which is also based upon the temperature change.
Leaves have a green color in the summertime when cholorophll metabolism is the greatest and they have a color change in the autum/winter months when the chlorophyll metabolism is the slowest.
There is a well explained answer from the following Wisteme site. It's a little bit long, but I think I explains the question in every details. Hope it helps and enjoy reading it.
let me guess homework problem... well it has to do with in the summer there is more liht being absorbed into the leaf so all the colors but green absorb (an object is the color of what it reflects) but then in fall less light gets into the leaf so diff. light is absorbed and reflected