biology eoy - y9

Osmosis

The net movement of water molecules across a semipermeable membrane from an area of low solute concentration to an area of high solute concentration, down the water concentration gradient, without requiring energy.

Hypotonic Solution

A solution with less solute than solvent, causing water to move into the cell, leading to swelling or bursting.

Hypertonic Solution

A solution with more solute than solvent, causing water to move out of the cell, resulting in shrinking or shriveling.

Isotonic Solution

A solution where water moves equally in and out of the cell, maintaining equilibrium with equal solute and solvent concentrations.

Factors Affecting Osmosis

Includes concentration gradient, temperature, surface area to volume ratio, and permeability of the membrane.

Diffusion

The net movement of particles from an area of high concentration to an area of low concentration.

Active Transport

The movement of a substance against a concentration gradient, requiring energy from cellular respiration and involving carrier proteins and ATP.