Lesson 3 - Lesson 3 Transport Throughout the Plant Body Overview of Transport How can water move form roots to top of all trees Water moves

Lesson 3 - Lesson 3 Transport Throughout the Plant Body...

This preview shows page 1 - 2 out of 9 pages.

Lesson 3: Transport Throughout the Plant Body Overview of Transport How can water move form roots to top of all trees? Water moves unidirectional UPWARDS Carbohydrates move bidirectionally in the plant Local Changes Result in Long Distance Movement Water and dissolved minerals travel great distances in xylem o Most of the force is “pulling” created by transpiration o Cohesive and adhesive forces Create a continuous column of water o Some “pushing” comes from pressure of water entering roots Transport between cells Aquaporins Once thought water moved across plasma membranes only by osmosis through lipid bilayer Osmosis is enhanced by membrane water channels called aquaporins Channel proteins that allow selective movement of water molecules from one side of the membrane to the other Can’t change direction of water movement, but can speed up diffusion process Water Potential Potentials are a way to represent free energy Water Potential is used to predict which way water will move Measured in units of pressure called megapascals (MPa) Water will always move form an area of higher water potential to an area of lower water potential ******Calculation of Water Potential Water potential has 2 components 1. Pressure Potential
Image of page 1
Image of page 2

  • Left Quote Icon

    Student Picture

  • Left Quote Icon

    Student Picture

  • Left Quote Icon

    Student Picture