[JZ_1]

I hope this is random enough for you to answer this question in this forum

I was doing my HW while i felt hungry
hw:
http://www.chemicalforums.com/index.php?board=4;action=display;threadid=4284

i got a banana and i ate it..(dont worry this story is short)..then i put a few drops (5 or more) isopropyl alcohol on one of the inside peel of the banana .
i put water on another...

the alcohol was absorbed while the water was blocked (semi-permeable membrene)

the alcohol made the banana rot...i want to ask WHY???

..try this yourself .

also..i want to ask...HOW DO U DELETE A new topic...?

[billnotgatez]

Interesting experiment!
I think this entry could also have been posted in Citizen Science Forum.

I try to eat bananas regularly so I might try this experiment.

Did you use household or reagent isopropyl?

Regards,
Bill

[ATMyller]

Isopropyl alcohol dissolves cell membranes' lipides. You'll get similar result with other nonpolar solvents etc. gasoline.

[JZ_1]

Since it is nonpolar.....how do they keep the water...in the isopropyl alcohol mixed..(ie: 70% isopropyl alcohol by volume…active indegredient also contains water).

are u suggestin gthey are tricking you, giving you less for your money?

http://en.wikipedia.org/wiki/Isopropanol
LOOK under uses...how does it dissolve water??

"The isopropanol does not remove the water from the gasoline. Rather, the isopropanol solublizes the water in the gasoline..."

[Yggdrasil]

Whether a solvent is non-polar or polar is not an either/or sittuation.  There is a continuous scale of polarity.  Isopropanol can be considered a polar solvent.  The hydroxide group creates enough of a dipole for it to interact with many polar groups, and the hydroxide also enables it to hydrogen bond to (making is a protic solvent as well).  However, the hydrocarbon chain gives it some qualities of a non-polar solvent as well.  Therefore, isopropanol is still a polar solvent, but it is considerably less polar than water.  Isopropanol can still disolve water (probably because of its ability to hydrogen bond), but since it has some non-polar characteristics, it can disolve some organic compounds that are insoluble in water -- for example, membrane phospholipids (in the OP's example) or pen ink.  Similarly, since it is less polar than water, isopropanol cannot disolve some highly polar/ionic compounds that are soluble in water, such as NaCl.

[Dude]

How quickly does the banana turn black and rot after exposure to IPA?  Dissolution of a lipid should not discolor the banana.  I would suspect that the IPA triggers some type of enzymatic ripening process similar to ethylene.

[Yggdrasil]

My guess that the phenomenon JZ_1 observed is not rotting, but bruising.  Bruising comes about when the membrane-bound structures (such as the vacuoles) within a plant are ruptured (lysed).  Since the IPA will dissolve membrane phospholipids, it will cause lysis.  But, this is just my guess, and I'm not completely sure this explanation is correct.

[JZ_1]

yea..it may probably be brusing...

but it doesnt bruise quickly...itz kind of an over time thing...2 min... i dunno

i'm out of bananas ...hehe...