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Photosynthesis & nitrogen
Roger Miller correctly stated:
> Photosynthesis does not consume nitrogen.
"Moontanman", asked:
> Your proof of that would be located where?
He added further:
> Stephen Spotte in his book "Sea Water Aquariums' states that all plants
use
> nitrogen in some form...
Your reference to Spotte is correct, plants do use nitrogen in some form for
the synthesis of amino acids. But Roger's statement was quite specific - and
involved PHOTOSYNTHESIS alone. Nitrogen is not involved directly in the
photosynthetic reaction, which is really just how green plants are able to
convert the energy inherent in light photons and store it in chemical form
(simple sugars):
light
CO2 + 2 H2O ------------> (CH2O) + O2 + H2O
green plants
Moon continues:
> Nitrogen is assimilated during photosynthesis to make
> the amino acids inside cells.
That should be "during growth", not "during photosynthesis"
> Plants get theirs [nitrogen] by assimilating those compounds
> from their environment and using them by way of photo synthesis
> to make new body tissues.
All that plants get from photosynthesis is simple sugar(s). [I don't mean to
belittle the process, it is a miracle.] They get everything else from the
synthesis of other, more complex compounds, using the sugar(s) manufactured
during photosynthesis as the energy source. Nitrogen is involved in some of
those reactions, but they are not photosynthesis.
Moon concludes with:
> Plants make their tissue by photosynthesis,
> I don't know how to be more basic than that.
Plants make simple sugars by photosynthesis (see above...). They make
everything else by other reactions with other names.
For reference, take your pick of either of the following:
ESG Biology Hypertextbook, developed at MIT -
http://esg-www.mit.edu:8001/esgbio/ps/psdir.html
Encyclopaedia Britannica's entry on Photosynthesis -
http://www.britannica.com/bcom/eb/article/0/0,5716,115112+1+108553,00.html
Both should prove authoritative enough to resolve your doubts.
James Purchase
Toronto