Photosynthesis

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rosebud
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Photosynthesis

Post by rosebud » Sun Nov 06, 2005 11:45 am

Please can somebody help me with the following questions-:

Explain why, in a young plant, you would expect the rate of photosynthesis to be greater than the rate of respiration over a 24-hour period.


By which two methods do substances pass from the cytoplasm of a cell, through a membrane, into a chloroplast.

I think it is Diffusion and Active Transport.

Thanks for your help
:P

fran008
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Post by fran008 » Sun Nov 06, 2005 3:48 pm

Well i guess its because the plant has still to make what it needs to respire...its source from the cotyledon is decrasing and it needs to synthisis fructose fast

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Post by MrMistery » Sun Nov 06, 2005 5:20 pm

That is correct. At light intensity bigger than 500, the rate of photosynthesis exceds the rate of cellular respiration. This is for one simple reason: The plant needs to get it's energy in order to sustain itself from photosynthesis, but it also needs to grow.

On the second question, the correct answer is: passive transport and active transport
Passive transport includes both simple diffusion and facilitated diffusion-which takes place through ion channels and aquaporins. This particullar mechanism is very important as it takes place about 1000 times faster than transport through other proteins.
Under active transport you have primary active transport and secondary active transport(according to a created gradient)
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rosebud
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Post by rosebud » Sun Nov 06, 2005 11:13 pm

Thanks

:D

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MrMistery
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Post by MrMistery » Mon Nov 07, 2005 6:27 pm

You're welcome. Photosynthesis is one of my hobbies
"As a biologist, I firmly believe that when you're dead, you're dead. Except for what you live behind in history. That's the only afterlife" - J. Craig Venter

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