water transport in plants.

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NewtoBiology
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water transport in plants.

Post by NewtoBiology » Sat Sep 13, 2008 1:12 am

Hello Plant Biologists.

Would someone be so kind as to explain which of the following two sentences is false.

1. weak bonding between water molecules and the walls of xylem vessels or tracheids helps support the columns of water in the xylem

2. Gymnosperms can sometimes develop especially high root pressure, which may account for the rise of water int all pine trees wtihout transpirational pull.

I have been leaning towards #2 to be false, however I am torn because #1 could be false too because there is strong bonding between water molecules and the walls of xylem vessles and tracheids.

Can someone shed some light on my dilemma.

Thank you!

New to Biology.

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MrMistery
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Post by MrMistery » Wed Sep 24, 2008 2:27 am

2 is false. the bonds between water molecules are H bonds, which are not that strong(deltaG~1kcal/mol). Everyone seems to overestimate H bonds..
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mith
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Post by mith » Wed Sep 24, 2008 3:21 am

transpiration does not equate root pressure
Living one day at a time;
Enjoying one moment at a time;
Accepting hardships as the pathway to peace;
~Niebuhr

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MrMistery
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Post by MrMistery » Fri Sep 26, 2008 1:28 pm

Lol, none of us answered the question to avoid doing hw questions, but we each answered half :lol:
"As a biologist, I firmly believe that when you're dead, you're dead. Except for what you live behind in history. That's the only afterlife" - J. Craig Venter

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