At 4:55 PM 8/11/96 -0700, Marvin Adams wrote:
> I taught high school Biology several years ago and one
>of my former students was talking to me today and asked, "What
>is the gas found inside a pumpkin and where does it come from?"
>I would think that the wax cuticle on the outside of the pumpkin
>would keep air exchange to a minimum so I have no idea.
Marvin,
This is probably known...I don't know the answer...
but I would be shocked if the cuticle kept much gas
out (or in). Most waxes reduce water movement, but
gases are quite another kettle of fish. Because
the atmosphere is 70%+ Nitrogen, I'd bet that the
fruit contains at least that much...maybe more.
The oxygen content is probably lower than ambient
as the fruit wall maintains itself chiefly by
respiration (sure the skin does some photosynthesis
in early stages, but I'm assuming you are talking
about a ripe pumpkin). The carbon dioxide level
is probably somewhat higher than ambient for the
same reasons. The ripening fruit probably makes
a certain amount of ethylene...probably well above
ambient but still "trace" levels unless the fruit
is DEAD ripe. These are just some guesses...maybe
someone knows who did a real gas analysis and what
the results were.
ross
______________________________________________________________
|
Ross Koning | Koning at ecsu.ctstateu.edu
Biology Department | http://koning.ecsu.ctstateu.edu/
Eastern CT State University | Phone: 860-465-5327
Willimantic, CT 06226 USA | Fax: 860-465-5213
____________________________|_________________________________
Plant Physiology is Phun!
/\|___/\ //\______COOH NH-CH2-CH=C-CH2OH \/OH
| | | | | | || //\___ \CH3 /\|/\\/\\COOH
\/ \/|\/| \\/ \ / N || N | |
/\ | |__|= NH | || || //\//\
| COOH \\ /\ / O
COOH H2C=CH2 N NH
______________________________________________________________
