Passive Transport
Direction: ______High_____ to _low_________ concentration.
Active Transport
Direction: ___Low___ to __High___ concentration.
****With/along the concentration gradient.
****Against the concentration gradient
Energy: YES or NO
Energy: YES or NO
Examples:
Examples:
1. _____simple diffusion________________
a. Diffusion of molecules
2. _________osmosis_________________
a. Diffusion of water
3. _________facilitated_______________
a. Uses a carrier protein
Case Studies: Indicate which type of passive transport is occurring in
each case.
1. Food coloring dispersing in a glass of water .
_________simple diffusion_____________
1. _Sodium-Potassium Pump___
a. 3 Na+ out, 2 K+ in
2. __Exocytosis____
a. Vesicle fuses to membrane to release molecules
3. __Endocytosis________
a. Vesicle fuses to membrane to take in molecules
Case Studies: Indicate which type of active transport is occurring in
each case.
1. Sodium and potassium ions traveling AGAINST their
concentration gradient. _ Sodium-Potassium Pump ____
2. Movement of LARGE molecules through a transport
protein._Facilitated Diffusion_______________________
2. A cell using a VESICLE to take in important nutrients.
_______ Endocytosis _____________
3. Ions moving through ion channels.
__Ion channel or Facilitated diffusion______
3. A cell getting rid of waste materials using a VESICLE.
_________ Exocytosis _________
Solutions
Homeostasis and the Membrane
1. The type of molecules that makes up the lipid bilayer is a _
phospholipid __ molecule.
2. The outside of the lipid bilayer is _hydrophilic_ (loves water)
and the inside is _hydrophobic__ (hates water).
1. The solute is _ Sugar __________ ( the substance being
dissolved)
2. The solvent is __ Water_________________ ( the substance
that does the dissolving)
3. A _ Solution _____ is the mixture of the solute and the
solvent.
3. The cell membrane also contains _proteins_ and __
carbohydrates__.
Types of solutions:
Cell
A
B
C
4. Solution A is __ Isotonic Solution _____
A. A cell in this solution will __ be at steady state __
5. Solution B is __ Hypertonic Solution ____
A. A cell in this solution will __ Shrivel/Shrink ____
6. Solution C is ___ Hypotonic Solution ___
A. A cell in this solution will __ Swell and Burst __
4. The cell membrane is _selectively__ _permeable__ which
allows the cell to control what enters and leaves. This
maintains the HEALTH of the cell.
5. Membranes help to maintain _homeostasis or equilibrium_
(steady state) by regulating the movement of molecules.
6. Molecules will eventually become BALANCED /
UNBALANCED on both sides of the membrane.
Practice Questions
1. Explain the process illustrated in the diagram.
High Concentration
Fluid
OUTSIDE the
cell has:
Lower water
molecule
concentration
(high solute)
Then the
fluid is:
Water will
diffuse:
???
Out of the
cell
How the cell
is
affected:
Shrink
____ 13. 3. The term missing from the chart above is
A. hypertonic.
C. isotonic.
B. hypotonic.
D. equilibrium.
Low Concentration
4. Which of the following is not part of the cell membrane?
A. Passage of water molecules through a semi-permeable
membrane to equalize concentration.
B. Movement of molecules against a concentration gradient
expanding energy.
C. Separation of suspended particles from fluid environment
through a porous membrane.
D. Transport of molecules across a membrane from a high to low
concentration gradient by means of a carrier molecule.
2. How does the cell membrane in the drawing below help to
maintain the health of this cell?
A.
B.
C.
D.
By providing support and structure for the cell.
By manufacturing protein to provide energy for the cell.
By regulating the transport of materials in and out of the cell.
By storing food as future energy for the cell.
A.
B.
C.
D.
carbohydrates
phospholipids
Nucleic acids
cholesterol
5. The interior of the plasma membrane is
A. hydrophobic
B. hydrophilic
C. polar
D. concentrated