The Cohesion Tension Theory

Water is a polar molecule.  When water molecules approach they form a Hydrogen Bond.  The negatively charged oxygen atom of one water molecule forms a hydrogen bond with the positively charged hydrogen atom in another water molecule.

Water enters the xylem in the roots by Osmosis.  Once in the xylem the water molecules hydrogen bond forming a continuous string of water molecules up to the leaf.

Water is constantly lost by Transpiration in the leaf.  When one water molecule is lost another is pulled along.  Transpiration pull is the main cause of water movement.

 
Back
Reproduction without permission is strictly prohibited.
© Copyright 1998 Terry Brown. All rights reserved.