Osmosis

• Osmosis is the diffusion of water molecules across a partially permeable membrane from a region of higher water concentration to a region of lower water concentration.
• Water concentration is the amount of water compared to the other molecules like sugars or salts that are dissolved in that water, also known as solutes.
• In a cell, the concentration of water is determined by the proportion of water compared to solutes, not the volume of water.
• Water particles will diffuse from the outside of the cell down the concentration gradient into the cell, a process known as osmosis.