Cellular Transport: movement of materials in and out of a cell  Homeostasis: combination of two words  Homeo = same  Stasis = steady  Homeostasis: the process of keeping internal conditions stable

Cell membrane: phospholipid bilayer

Types of Cellular Transport  Passive Transport  Diffusion  Facilitated diffusion  Osmosis  Active Transport  Endocytosis  Exocytosis

Diffusion: movement of molecules from an area of high concentration to an area of low concentration

Equilibrium: state of having equal concentrations

Facilitated Diffusion: the diffusion of molecules across a membrane through a special protein

Osmosis The movement of water across a membrane

Osmosis vs Diffusion: What is the difference?  Osmosis is always the movement of WATER  It moves water across a selectively permeable membrane through which the solute (dissolved particles) cannot cross

Three types of Osmotic solutions  You will see the following:  1. solute concentrations  2. arrows illustrating the direction of water  3. the type of solution

Hypertonic Solution

Hypotonic Solution

Isotonic Solution  Equal solute concentration on the outside and inside of the cell

Hypotonic IsotonicHypertonic Osmosis on Animal Cells

Osmosis on Plant Cells

Active Transport  Movement of a substance across an area of low concentration to high concentration that requires energy  Two types  Endocytosis  Exocytosis  Uses a transport protein to help it enter or leave the cell: carrier, channel, or gate

Endocytosis  Process in which a cell take IN a large particle EnterCellProcess

Exocytosis  Process in which a cell releases materials out of the cell