Date: Thu, 24 Jul 1997 07:57:42 -0400 From: Alastair <Alastair_R@compuserve.com> To: cp@opus.hpl.hp.com Message-Id: <aabcdefg2774$foo@default> Subject: Transpiration &c.
As people have said, transpiration is indeed the loss of water through th=
e
stomatal openings of leaves, but they should be aware of one or two error=
s
in what they have said...
>>...transpiration...I believe that this infact occurs at night when the
plans' stomata open
For the majority of plants, it is via the stomata the air gets into the
leaves at all, and except in xerophytes <effectively desert plants...> th=
ey
tend to be open in greatest numbers mainly in the day which is why most
water is lost at this time, not at night when water loss is much reduced.=
>>in effect, "Plant sweat" or perspiration
More akin in fact, to the water we lose from our airways. Guttation, on
the other hand, is a bit more like sweating if one has to compare <g>
>>*'respiration' is breathing in oxygen, combining it with food to
>>make energy, and giving out carbon dioxide waste. Plants do this
>>(all the time I think) just like humans do.
Respiration is the AEROBIC oxidation of food molecules, by organisms, to
release energy. That is to say that it is the catabolism of molecules,
rather than combination, during which CO2 and H2O are evolved as waste
products. Note that overall, respiration is the means by which energy is=
released to drive chemical pathways in aerobes, therefore most organisms
<being aware of course that many others don't do it this way> of this kin=
d
must respire, to varying degrees, all of the time.
I don't mean to be a pedant or anything <g>, just trying to make myself
useful...
All the best, =
Alastair.
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