NAME ________________________________
CLASS_______
The Cell in It’s Environment
A review of osmosis, diffusion, passive and active transport, and tonicty
1. Active transport requires Energy to move molecules across membranes.
2. _ATP is the molecule that provides the energy for active transport.
3. _DIFFUSION moves oxygen and carbon dioxide molecules from an area of high
concentration to an area of low concentration across membranes.
4. The cell organelles that burns glucose and provides ATP for active transport are
the_MITOCHONDRIA
5. Water moves across membranes by _OSMOSIS
6. _PASSIVE transport does NOT REQUIRE energy.
7. A cell placed in an _ISOTONIC solution neither swells or shrinks because the
concentration of molecules outside the cell is the same as inside.
8. A solution in which there is a HIGHER concentration of dissolved molecules
OUTSIDE the cell than inside _HYPERTONIC
9. A CONCENTRATION _GRADIENT forms whenever there is a difference in
concentration between one place and another
10. A solution in which the concentration of dissolved molecules outside the cell is
LOWER than inside = _HYPOTONIC
11. When molecules move from high to low along a concentration gradient we
say they are moving “_DOWN_” the gradient.
12. The shrinking of a plant cell membrane away from the cell wall when placed in
a hypertonic solution is called _PLASMOLYSIS
\Describe diffusion:
NAME ________________________________

Moves things into/out of the cell (circle one or both!)

Moves down/against concentration gradient (circle one)

For large/small molecules (circle one or both!)

Uses/does not use protein doorway (circle one)
Describe osmosis:
 Moves things into/out of the cell (circle one or both!)

Moves down/against concentration gradient (circle one)

For large/small molecules (circle one or both!)

Uses/does not use protein doorway (circle one)
Describe passive transport:
 Moves things into/out of the cell (circle one or both!)

Moves down/against concentration gradient (circle one)

For large/small molecules (circle one or both!)

Uses/does not use protein doorway (circle one)
Describe active transport:
 Moves things into/out of the cell (circle one or both!)

Moves with/against concentration gradient (circle one)

For large/small molecules (circle one or both!)

Uses/does not use protein doorway (circle one)
Describe facilitated diffusion:

Requires/does not require energy (circle one)

Requires/does not require a transport protein (circle one)

Moves down/against concentration gradient (circle one)

Moves things into/out of the cell (circle one or both!)
CLASS_______
NAME ________________________________
CLASS_______
In the pictures below the dots represent molecules that are dissolved in the water both inside
and outside the cell. On the line, write whether the solution surrounding the cell is hypotonic
hypertonic or isotonic.
Hypotonic
Hypertonic
Isotonic
Determine what type of solution each of the cell pictured must be sitting in by looking at the
condition of the cell. Write hypotonic hypertonic or isotonic solution on the line.
___Hypo_______
___Hypo_______
__Iso___ ___Hyper__________
__Iso___ ___Hyper__________
NAME ________________________________
CLASS_______
Use the pictures on the left to answer the questions on the right.
After digestion:
= glucose molecule
blood
cell
a. Which side has the higher concentration of glucose?
_____________Blood__________________________
b. Which way will the glucose go? ___Into the
cell_____________________
c. Does this require energy?
__________No__________________________
d. Is this active or passive transport?
____________Passive______________________________
_
Easter egg coloring:
A blue food coloring tablet is placed in a cup of vinegar and water. The blue tablet will
dissolve and spread evenly throughout the liquid.
beaker
Blue food
color tablet
a. Is this diffusion or osmosis? ____Diffusion_____
b. Does this require energy? ____No_________
c. Is the blue dye going from a lower to a higher concentration,
or from a higher to a lower concentration? ______________
Water and vinegar
Plant cell after being over-watered.
a. Water rushes into the plant cell’s vacuole. Is this
diffusion or osmosis? ____________________
Plant cell after not being watered lately, so it has begun to wilt:
a. Which way did the water move? Into the vacuole, or out of
the vacuole? ______________________
b. By what process will the water move?
________Osmosis______
NAME ________________________________
CLASS_______
Observe the diagrams in the table below. Assume that the dots are dissolved particles on either
side of the cell membrane. They are like oxygen molecules that can diffuse across the cell
membrane. Do the following situations represent concentration gradients? If so, in which
direction would diffusion occur? (MOVEMENT OF THE PARTICLES)
1) Yes, Right
2) No, None
3) Yes, right
Observe the diagrams in the table below. Assume that the dots are dissolved particles (like
protein or carbohydrate molecules) on either side of the cell membrane. Do the following
situations represent concentration gradients? If so, in which direction will osmosis occur?
MOVEMENT OF THE WATER – MOVES FROM HIGH TO LOW
1) Yes, Left
2) No , None
3) Yes, Left