Download cell exchange2

Chapter 4
Exchange
with the Environment
Cell Energy
The Cell Cycle
This chapter answers the
Essential question on cells:
Fluency Chart
diffusion
osmosis
endocytosis exocytosis
Active
transport
Passive
transport
Section 1
Exchange with the
Environment
Movement of “Tiny”
particles:
Called Diffusion.
The movement of particles from high
concentration to an area of low
concentration.



Happens in gases, liquids, and solids
Ex. Of tiny particles: O2, H20, CO2
Gases diffuse in other gases…
Liquids diffuse into other
liquids…
Solids diffuse into other
solids…
Particles always move…
Brainpop
It’s about the membrane
silly!
•The membrane is made of phospholipid molecules. They
have two parts to them. One is the two hydrophobic
tails. The other is the hydrophilic head.
Diagram of a
membrane:
Plant and Animal Cell Rap
OSMOSIS:
H20 across a cell

A special diffusion of
membrane

Water moves from high concentration
to low concentration
Osmosis…
Diagram of how osmosis works:
Extreme osmosis:
Tap the cell
A comparison……
osmosis
diffusion
both
Movement of “small ”
particles:
Examples are sugars or amino acids
 These can’t pass through the
“phospholipid molecules” in the cell
membrane
 Need special protein channels to get
in.


TWO types of movement:
1) Passive transport
Particle diffuses through protein
channels from an area of high
concentration to an area of low
concentration
 Does not require any energy

2) Active Transport

Movement of particles through proteins
protein
channel
against the normal direction of
diffusion.

(low to high concentration)

Requires the cell’s
ATP (needs energy)
Diagram of active transport:
Passive and Active Transport
Active
Passive
Both
CELL MEMBRANE:
Tap the
pic.
Moving Large Particles:

Two ways :

1) Bringing things in…Endocytosis

2) Getting things out of the cell…
Exocytosis video
Animation of exocytosis:
Concept map…