Transcript Diffusion and Osmosis Notes

Moving Cellular Materials
SOL BIO 4.d
Fluid Mosaic Model:
A mosaic is a
structure made
up of many
different parts.
The plasma
membrane of a
cell is composed
of different
kinds of
macromolecules.
Phospholipid
bilayer
Passive Transport:
• PASSIVE TRANSPORT- DOES NOT
require energy to move materials through
the cell membrane
3 Types of Passive Transport:
1. DIFFUSION- molecules of a substance
will move from an area of high
concentration to an area of low
concentration until they reach
equilibrium
• Diffusion occurs in cells when substances
(O2,CO2, salts, sugars, amino acids) that
are dissolved in H2O move from an area of
higher concentration to an area of lower
concentration.
3 Types of Passive Transport:
3 Types of Passive Transport:
3 Types of Passive Transport:
DIFFUSION
3 Types of Passive Transport:
2. OSMOSIS (diffusion of water)-the
movement of water molecules through a
semi-permeable membrane from an area
of greater water concentration or pressure
to an area of lesser water concentration or
pressure
3 Types of Passive Transport:
OSMOSIS
3 Types of Passive Transport:
• Hypertonic- too much solute, not
enough water; cell will shrink & wrinkle
• Hypotonic- too much water, not enough
solute; cell will swell up, expand
• Isotonic- equal parts water and solute;
water moves in & out of the cell in
dynamic equilibrium
3 Types of Passive Transport:
OSMOSIS
3 Types of Passive Transport:
OSMOSIS
3 Types of Passive Transport:
3. FACILITATED TRANSPORT- requires
transport proteins in the cell membrane to
move materials into and out of the cell
3 Types of Passive Transport:
FACILITATED TRANSPORT
Active Transport:
• ACTIVE TRANSPORT- requires ENERGY
to move materials through the cell
membrane
Active Transport:
2 Types of Active Transport:
• ENDOCYTOSIS- requires ENERGY to
move materials INTO the cell membrane
• EXOCYTOSIS- requires ENERGY to move
materials OUT OF the cell membrane
Active Transport:
Active Transport:
Active Transport: