Cellular Transport PPT notes
What must cells take in to survive? Nutrients
What part of the cell allows it to take in nutrients and water? Cell membrane
Does it have another name? Plasma membrane or Phospholipid bilayer
What is the cell membrane made of? Proteins and phospholipids
What is the process for cells to move substances through the cell membrane? Transport
Two Types of Transport
Passive transport
Active transport
Passive Transport
What is Diffusion or Passive Transport?
High
1. Requires no energy
2. Molecules move from high to low concentration
3. Molecules move with the concentration gradient.
“Go with the flow”
Low
The purpose of diffusion is to reach Equilibrium
Types of Passive Transport
Osmosis
The diffusion of water across a
semi-permeable membrane.
Water wants to water “stuff”
down.
“Salt sucks”
Facilitated Diffusion
Diffusion of large or polar
molecules through protein
channels.
“helped diffusion”
Explain what is happening during osmosis. The _water__ molecules are moving from __high
concentration to __low concentration in order to reach __euilibrium___.
In other words…. Water moves to wherever there is more “stuff” like salt, sugar, etc. More stuff
means less water. “salt sucks”.
OBSERVATIONS OF OSMOSIS
80%
H2O
80%
H2O
100% Distilled
Water
Hypotonic solution
80% Water
20% Isotonic solution
Dissolved
Substances
80%
H2O
70% Water
30% Hypertonic solution
Dissolved
Substances
What is a Hypertonic solution? What happens
to the cell in this solution?
Hypertonic has more “stuff” in it than the cell. The cell loses water and shrinks.
What is a Hypotonic solution? What happens
to the cell in this solution?
Hypotonic has less “stuff” in it than the cell. The cell gains water and swells (possibly pops or
lyses)
What is an Isotonic solution? What happens
to the cell in this solution?
Isotonic has the same amount of “stuff” as the cell. Water moves in both directions equally
(equilibrium).
Help Wanted! Explain facilitated diffusion: Larger molecules can’t just diffuse across the cell
membrane, they need a “doorway”. Proteins that are in the cell membrane act like doorways.
Some are like hallways and some are like swinging doors.
Review
D
F
A
C
B
E
.
.
.
.
.
.
1.
2.
3.
4.
5.
6.
Cell membrane
Proteins and lipids
Active and Passive
Diffusion
Osmosis
Facilitated diffusion
a.
b.
c.
d.
e.
f.
two types of transport
movement of water across a membrane
movement of substances across a membrane
part of the cell that regulates what goes in and out
movement assisted with channel proteins.
two components of the cell membrane
ACTIVE TRANSPORT
How is Active Transport different from Passive Transport?
High
1. Active transport requires energy
2.Molecules move from low concentration to high concentration
3. Molecules move against the concentration. “Swimming against the flow”
Low
Types of Active Transport
Enters the cell
Endocytosis
Engulfs particle
Phagocytosis: cell
eating
passive
transport
active
transport
Exits the cell
Exocytosis
Liquids
Pinocytosis: cell
drinking
Review
energy
concentration
gradient
Not needed
High to low
Goes with the
flow
Goes against the
flow
Requires energy Low to high
What part of the cell is used to bring in particles? Cell membrane
How does a cell (including white blood cells) take in LARGE particles? Phagocytosis
How does a cell take in small or liquid particles? Pinocytosis