1. BIOLOGY Unit 2 Notes: Cell Membrane Transport

2. (1) Cell Membrane Transport
Why Do Cells Do This? Cells need to move useful nutrients and molecules in and out of the cell .
Types of Transport:
Diffusion
Facilitated Diffusion
Osmosis
Active Transport

4. (2) Diffusion
Movement of particles from high to low concentration, across a concentration gradient, until reaching equilibrium.
Does NOT require any energy (or ATP).

6. (3) Facilitated Diffusion
The assisted movement of large molecules across protein channels, from high to low concentration, until reaching equilibrium.
Does NOT require any energy (or ATP).

8. (4) Osmosis The diffusion of water.
The movement of water molecules from high to low concentration, across a gradient, until reaching equilibrium.
Does NOT require any energy (or ATP).

10. (5) Osmotic Environments
Isotonic Environment: When there is an EQUAL concentration of water inside, and outside the cell.
Hypertonic Environment: When there is a HIGHER concentration of water inside the cell, than outside.
Hypotonic Environment: When there is a LOWER concentration of water inside the cell, than outside.

11. (6) Active Transport
The forced movement of particles, AGAINST a gradient, from low to high concentration.
Requires the use of energy (or ATP).