Cell Transport Notes Cell Membrane Also known as

Cell Transport Notes

Cell Membrane • Also known as the lipid bilayer • Structure: 2 layers of phospholipids • Function: Regulates what comes into and out of the cell

Lipid bilayer (phospholipids) make up the membrane with proteins embedded to help regulate what comes across the membrane

Single Membrane lipid Draw this!

Other molecules in the Cell Membrane: Proteins- form channels and receptors Carbohydrates- identify cell

Why do we need protein channels? • The membrane is semi-permeable (It lets some molecules pass through but others cannot) • Things that can pass: small, non polar molecules • Things that can’t pass: large or charged molecules

Cell Transport Special Vocab Concentration- number of particles in a given volume Equilibrium- concentration is the same inside and outside the cell

Types of Cell Transport we will be learning Passive Transport- does not require energy 1) Simple Diffusion 2) Osmosis 3) Facilitated diffusion Active Transport- requires energy 1) Protein pump 2) Endocytosis 3) Exocytosis-

Passive Transport- does not require energy Types of Passive transport 1) Simple diffusion 2) Osmosis 3) Facilitated diffusion

Simple Diffusion - Passive, doesn’t require energy - Molecules move from areas of HIGH concentration to LOW concentration

Simple Diffusion Equilibrium

Osmosis • The diffusion of water through a semi-permeable membrane

SALT SUCKS

In osmosis, water always goes to the hypertonic solution!!!

Facilitated Diffusion • Requires carrier protein • Does not need energy!!!!

Passive Transport Summary • Simple Diffusion - molecules move from high • • concentration to low concentration (down the slide) Osmosis- diffusion of water Facilitated Diffusion- diffusion that uses a carrier protein

Active Transport Goes against the gradient and requires energy!!!

Protein Pumps • Pumps materials AGAINST the gradient UP THE SLIDE!!!!

§ Exocytosis- transport of very large materials outside the cell § Endocytosis- transport of very large materials into the cell (phagocytosis & pinocytosis)

Types of Endocytosis 1) Pinocytosis- “cell drinking”, absorbing liquids into the cell the 2) Phagocytosis- “cell eating”, absorbing food into cell