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
- Slides: 21