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Re: Mass/Energy Conservation



OK; O2 mass input is probably > CO2 mass out. So we do photosynthesis,
except it's the reverse, oxidation -- see Krebs cycle; someone, not I, can do
the balances of the eq's and come up with the correct answer.. This also
assumes that the Krebs cycle dominates all the mass exchange processes.

bc

Oh! http://www.chem.wsu.edu/Chem102/102-CitrAcCycOxPhos.html#input

P.s. Plants do this at night - do they lose weight then?

Joel Rauber wrote:


I must be missing something here, but I thought we didn't engage in
photosynthesis!

bc


Short response: we engage in respiration in addition to digestion.

Longer response: If one is going to argue against the proposition that you
can gain two pounds, when you only ingested one pound of chocolate cake you
need to consider other mass inputs besides what goes down the esophagus.
Without considering rather ridiculous ideas (like dust collecting in your
hair), I came up with the idea that we breath and perhaps that respiration
might involve a net gain in mass through respiration combined with
digestion. Which gets down to whether or not digesting your food might
combine with some of the mass you input through the lungs with what you
input in your stomach making for a net gain over and above the mass input
going down the esophagus.

Joel Rauber
Joel_Rauber@sdstate.edu
Joel Rauber wrote:

BTW, what's the point of Dave A.'s initial question anyway?



David Bowman
David_Bowman@georgetowncollege.edu


While I can't answer for Dave A. I can say that when I have asked myself
this question I was motivated by the oft heard statements along
the lines of
" I ate a pound of chocolate cake and gained two pounds". So I
asked myself
the question, is it possible gain more weight than the weight
of the food
you ingest through the mouth that goes down the gullet to your stomach?

cut

Joel Rauber
Joel_Rauber@sdstate.edu