Transcript Ch. 7.3 Notes, Parts 2-4

Chapter 7-3 Notes Part 2
Types of Transport
TRANSPORT CAN BE
EITHER
DRAW
Passive Transport
• On top of the hill
Weeee!!!
• Movement of molecules from
areas of high concentration
to areas of lower
concentration.
• DOES NOT REQUIRE
ENERGY!!!
high
low
OR
Active Transport
DRAW
• Bottom of the hill
This is
gonna
be hard
work!!
• Movement of
molecules from areas
of low concentration to
areas of high
concentration.
high
• REQUIRES
ENERGY!
low
•Animations of Active
Transport & Passive
Transport
•
Types of Passive Transport
cell does not use energy
1. Diffusion
2. Facilitated Diffusion
3. Osmosis
•
Types of Active Transport
cell uses energy
1. Protein Pumps
2. Endocytosis
3. Exocytosis
All 3 types of PASSIVE transport occur
until equilibrium is reached.
Equilibrium:
• when the concentration of a solute is the
same throughout a closed system. (i.e.
Inside and outside of a cell.)
Three Types of Passive
Transport Defined
1. Diffusion: movement of molecules FROM areas of
HIGH concentration TO areas of LOW
concentration through the lipid bilayer. Examples:
Alcohol, CO2, O2
GO TO DIFFUSION ANIMATION
Simple Diffusion Animation
http://bio.winona.edu/berg/Free.htm
2. Facilitated Diffusion A
Diffusion of specific particles
through transport
proteins found in the cell
membrane
Example:Glucose
a.Transport Proteins are
specific – they “select”
only certain molecules
to cross the membrane
b.Transports molecules
that are large or
insoluble in lipids.
Facilitated
diffusion
(Channel
Protein)
Carrier Protein
B
Diffusion
(Lipid
Bilayer)
3. Osmosis
3.Osmosis: diffusion
of WATER through a
selectively permeable
membrane.
a. Water moves from
high concentration of
(H2O)to low
concentration(of H2O)
Osmosis
animation
•Water moves
freely through
special pores.
•Solute (green)
soluble in lipids.
Ch 7-3 Notes Part 3
Effects of Osmosis on Life
i.
Cells can not control the movement of
water (Osmosis).
ii. If too much water moves into the cell
it can burst (die). If too much water
moves out it can shrivel up (die).
HOW DO
SOLUTIONS
AFFECT
OSMOSIS???
Hypotonic Solution
•
Osmosis
Animations for
isotonic, hypertonic,
and hypotonic
solutions
Hypotonic: has a lower concentration of solutes and a
higher concentration of water compared to inside
the cell. (Low solute; High water)
Result: Water moves from the solution into the cell)
Osmotic pressure increases and causes the cell to
grow until equilibrium is reached or the cell bursts.
Hint: HYPO=HIPPO(grow)
•
Hypertonic Solution
Osmosis
Animations for
isotonic, hypertonic,
and hypotonic
solutions
Hypertonic: The solution has a higher concentration
of solutes and a lower concentration of water than
inside the cell. (High solute; Low water)
Result: Water moves out of the cell into the solution:
Cell shrinks/shrivels.
•
Isotonic Solution(Iso=Equal)
Osmosis
Animations for
isotonic, hypertonic,
and hypotonic
solutions
Isotonic: The concentration of solutes and water in
the solution is equal to the concentration of solutes
and water inside the cell.
Result: Water moves equally in both directions
(Dynamic Equilibrium) and the cell remains same size!
What type of solution are these cells in?
TOO MUCH
OSMOTIC
PRESSURE!!!
1
2
3
Hypertonic
Isotonic
Hypotonic
*Which of these solutions do you think is used in an IV?
•
How Organisms Deal with
Osmotic Pressure
Paramecium
(protist) removing
excess water
video
1. A protist, like paramecium, has contractile
vacuoles that collect water flowing in and
pump it out to prevent them from overexpanding.
Contractile Vacuole:
2. Bacteria and plants have cell walls that
keep the membrane from bursting when
osmotic pressure increases.
3. Animal cells are bathed in blood. Kidneys
keep the blood isotonic by removing
excess salt and water.
Ch 7-3 Notes
Part 4: Active Transport
IV. Active Transport
A. Requires energy (going up hill)
B. Actively moves molecules to where they
are needed
C. Movement from an area of low
concentration to an area of high
concentration (remember: up the hill)
(Low  High)
D. Three Types of Active Transport
1) Protein Pumps
2) Endocytosis
3) Exocytosis
D. 3 Types of Active Transport
1.Protein Pumps –
Require energy
transport molecules
across membrane.
Example: Ions such as
Na+ and K+ in
Sodium / Potassium
Pumps, which are
important in nerve
responses.
Sodium
Potassium Pumps
(Active Transport
using proteins)
Protein changes
shape to move
molecules: this
requires energy!
Types of Active Transport
Continued.
• 2. Endocytosis: taking
bulky material into a cell
a. Uses energy
b. Cell membrane folds in
around food particle
“cell eating”
c. forms food vacuole &
digests food
d. This is how white blood
cells eat bacteria!
Types of Active Transport
3. Exocytosis: Forces
material out of cell in bulk
a. membrane surrounding the
material fuses with cell
membrane
b. Cell changes shape –
requires energy
EX: Hormones or
wastes being released
from the cell
Endocytosis &
Exocytosis
animations
Exocytosis