Download Cell Membrane and Transport HW

Name _______________________________________________________ Period ___________ Date ___________________
The Cell Membrane, Homeostasis, and Cellular Transport HW
Vocabulary
1. Cell membranes are _S __ __ __ __ __ __ __ __ __ __ _P __ __ __ __ __ __ __ __
because they allow certain molecules to pass through but keep others out.
2. When you make Kool-aid, the water is the _S_ __ __ __ __ __ __ and the Kool-aid powder is the
_S_ __ __ __ __ __ .
3. The swelling and bursting of animal cells when placed in a hypotonic solution is called
_C_ __ __ __ __ __ __ __ __.
4. The shrinking of a plant cell membrane away from the cell wall when placed in a hypertonic solution is
called _P_ __ __ __ __ __ __ __ __ __ __.
5. _O_ __ __ __ __ __ __ pressure is caused by water inside a plant cell pushing against the cell wall.
6. When molecules move from high to low along a concentration gradient we say they are moving
“_D_ __ __ __” the concentration gradient.
7. A solution in which the concentration of molecules outside the cell is LOWER than inside
= _H_ __ __ __ __ __ __ __ __.
8. A solution in which there is a HIGHER concentration of molecules OUTSIDE the cell than inside
= _H_ __ __ __ __ __ __ __ __ __.
9. A cell placed in an _I_ __ __ __ __ __ __ __ solution neither swells or shrinks because the
concentration of molecules outside the cell is the same as inside.
10. A_ __ __ __ __ __ __ __ __ __ are membrane proteins that create a passageway across cell
membranes for water molecules during _O_ __ __ __ __ __ __.
11. The cell organelles that burn glucose and provide ATP for transport are the
_M_ __ __ __ __ __ __ __ __ __ __ __,
12. D_ __ __ __ __ __ __ __ __moves oxygen and carbon dioxide molecules from a high concentration to
a low concentration across membranes.
OSMOSIS
Label the pictures below (isotonic, hypertonic, or hypotonic) Black dots represent solute molecules.
_________________
__________________
_________________
__________tonic means there is a GREATER concentration of solute molecules
OUTSIDE the cell than inside.
__________ tonic means there is a LOWER concentration of solute molecules
OUTSIDE the cell than inside.
__________tonic means there is the SAME concentration of solute molecules
outside the cell as inside.
The pressure inside a plant cell caused by water pushing against the cell wall is called
___________________ pressure.
The SWELLING AND BURSTING of animal cells when water enters
is called _________________________.
This happens when an animal cell is placed in a _________tonic
solution.
Placing plant cells in a HYPOTONIC solution causes the osmotic pressure to
increase
decrease
(Circle ONE)
The SHRINKING of plant cells when water leaves so the cell membrane
pulls away from the cell wall is called __________________________.
It happens when a plant cell is placed into __________tonic solution.
When water leaves a plant cell, the osmotic pressure will
increase
decrease
(Circle ONE)
The shrinking of ANIMAL cells that are placed in a HYPERTONIC solution is
called ______________________.
Cells stay the same size when placed in an ________tonic solution because the amount of water
leaving the cell is the same as the amount of water entering.
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Directions: Pictured below is a cross section of a typical cell membrane. Use the numbers and terms to color
each part. Color in the  with the color that you are using for that term in the diagram. Once you have colored
something one time, you should be able to find other examples of it in the membrane. Color all examples of it
you see. By the time you have finished, ALL parts of the membrane should be colored in.
1. Phospholipids-- 1a.  head
1b.  tail
2.  Cholesterol (another kind of
lipid)
3. Proteins -3a.  Integral Protein
3b.  Peripheral Protei
4.  Carbohydrates
5.  Protein Channels
6.  Cytoplasm
Use ARROWS to show the direction of water movement into or out of each cell. Color
and label the cell in an isotonic environment light blue, the hypotonic environment
yellow, and the hypertonic environment light green.
Match the description or picture with the osmotic condition:
A. Isotonic
B. Hypertonic
C. Hypotonic
_____
_____
_____
_____
_____
_____
_____
_____
_____
solution with a lower solute concentration
solution in which the solute concentration is the same
condition plant cells require
condition that animal cells require
red blood cell bursts (cytolysis)
plant cell loses turgor pressure (Plasmolysis)
solution with a higher solute concentration
plant cell with good turgor pressure
solution with a high water concentration
Label the tonicity for each solution (isotonic, hypotonic, or hypertonic):
__________________
________________
_________________
Composition of the Cell Membrane & Functions
The cell membrane is also called the
___________________ membrane and is made of a phospholipid
_____________________. The phospholipids have a hydrophilic
(water attracting) ____________ and two hydrophobic (water
repelling) ____________. The head of a phospholipid is made of
an alcohol and _______________ group, while the tails are chains
of ___________________. Phospholipids can move
_______________ and allow water and other _____________
molecules to pass through into or out of the cell. This is known as
simple ________________ because it does not require
_____________ and the water or molecules are moving
_______________ the concentration gradient.
SKETCH AND LABEL a
phospholipid coloring
the heads red and the
tails blue.
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Refer to the U-tube pictures above when answering the questions below.
1. Why did the number of water molecules on each side of the membrane change,
whereas the number of sugar molecules stayed the same?
2. How does the plasma membrane of a cell compare with the membrane in the U-
shaped tube?
3. Explain the behavior of water molecules in the isotonic solution.
4. Why does water enter a cell that is placed in a hypotonic solution?
5. What happens to the pressure inside a cell that is placed in a hypertonic solution?
6. What can happen to animal cells when placed in a hypotonic solution? Explain.