Download Moving Cellular Materials

UNIT 3 – Lesson 5 Notes
MOVING CELLULAR MATERIALS
Cell Membrane
What a Cell Wants:
OXYGEN
WATER
FOOD
What a Cell Does NOT Want:
WASTE
Passive Transport

The movement of substances through the cell
membrane without energy.
1.Diffusion (gas)
2.Osmosis (water)
3.Facilitated Diffusion
(food)
NO
ENERGY
required!
Diffusion
 The random movement of molecules from a high
concentration to a low concentration. (GASES)
 But what does having a high concentration mean?
 CLASS DEMO
Diffusion
 Molecules of a substance will continue to move
until the relative number of these molecules is
equal in both areas.
 This is called equilibrium.
Example: Oxygen from lungs diffuses into blood.
Simple Demo
Osmosis
 The diffusion of water molecules into or out of the
cell.
 Water moves from an area of higher water molecule
concentration to an area of lower water molecule
concentration.
Humm…sounds
just like
diffusion –
except it’s with
water!
Osmosis
 This movement will occur across a membrane.
 “Salt Sucks” – salt sucks water out of things.
Cell Exposed to
Pure Water
Normal Cell
Cell Exposed to Salt
Simple Demo
Osmosis in Strawberries
Facilitated Diffusion
 The diffusion of molecules across a membrane
with the help of transport proteins.
 Allows large molecules (food) to cross the
membrane.
Simple Demo
proteins
Active Transport
 ENERGY is required to move materials through a
cell membrane.
 A transport protein binds with the needed particle
to move it through the cell membrane.
Active Transport
 Molecules are moved against a concentration
gradient. They move from areas of low
concentration to areas of high concentration.
 Moves Waste With ENERGY
Simple Demo
proteins
Uses ENERGY
https://www.youtube.com/watch?v=STzOiRqzzL4
Endocytosis
 The process of taking substances into a cell by
surrounding it with the cell membrane.
 The cell membrane folds in on itself, enclosing the
item in a sphere called a vesicle. The sphere pinches
off, and the resulting vesicle enters the cytoplasm.
Exocytosis
 The process of getting rid of substances.
 The membrane of the vesicle fuses with the
cell’s membrane and the contents are
released.
Inside of Cell
Outside of Cell
https://www.youtube.com/watch?v=DuDmvlbpjHQ