In article <2ghd1k$4iv at mserv1.dl.ac.uk> "" <unknown at dl.ac.uk> writes:
>So, what is the real question here: does photosynthesis remove energy from
>the universe? (probably yes) or, does photosynthesis remove heat from the
>surrounding medium (cytosol and/or the air arround the plant - I would guess
>not).
Ever since this discussion started, I've been trying to decide why
we should care whether or not photosynthesis removes heat from its
surroundings. Heat isn't a state function, so it seems a little odd to
worry about it; change the conditions of the reaction (but not the
starting and finishing states), and the amount of heat taken in or given
out changes. Perhaps someone can then tell me why we should care about
the form of energy involved in photosynthesis. We can all agree that
photosynthesis is endoergic (Delta U > 0, where U is the internal energy).
Does anything else really matter?
Marc R. Roussel
mroussel at alchemy.chem.utoronto.ca
