Module 7: Transport in Plants

Diffusion

Movement of molecules along a concentration gradient.

Osmosis

Diffusion of water molecules through a semipermeable membrane.

Inhibition

Adhesion of water molecules to large molecules, causing swelling of tissues.

Active Transport

Movement of solutes against a concentration gradient, requiring energy.

Water Potential (Ψw)

A measure of the potential energy in water that influences its movement.

Turgor Pressure

Pressure within a cell due to water entering, pushing against the cell wall.

Plasmolysis

Loss of water through osmosis, causing protoplasm to shrink away from the cell wall.

Transpiration

Process of water vapor loss from the internal leaf atmosphere.

Source and Sink

Source is where food enters the phloem; sink is where food exits or is utilized.

Pressure-Flow Hypothesis

Explains movement of organic solutes in the phloem from source to sink.