Transpiration and Osmosis

What is Transpiration

evaporation of water from the leaf through the stomata.

What happens in the plant during the day?

1. The stomata are open (due to photosynthesis) which allows oxygen and carbon dioxide to diffuse out and into the cell.

2. Guard cells become turgid by water intake

3. It also loses water by transpiration

What happens in the plant at night?

The stomata closes by guards cells becoming flaccid.

How osmosis happens in the leaf during the day?

1. Light is detected in the guard cells

2. Potassium ions enter the cell. This lowers the water concentration in the cell. Water enters the cell by osmosis.

3. Potassium ions enter the cell. This lowers the water concentration in the cell. Water enters the cell by osmosis.

How does osmosis happen at night?

Potassium ions enter the cell. This lowers the water concentration in the cell. Water enters the cell by osmosis.

Definition of osmosis

is the net movement of molecules from a high to low concentration across a semi permeable membrane.

Definition of flaccid

Plant cell loses water, become shriveled and limp

Definition of Turgid?

is a plant cell that has absorbed water, causing it to swell and become firm.