NAME ________________________________
CLASS_______
The Cell in It’s Environment
A review of osmosis, diffusion, passive and active transport, and tonicty
1. Active transport requires _E_ __ __ __ __ __ to move molecules across
membranes.
2. _A_ __ __ is the molecule that provides the energy for active transport.
3. _D_ __ __ __ __ __ __ __ __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_M_ __ __ __ __ __ __ __ __ __ __ __.
5. Water moves across membranes by _O_ __ __ __ __ __ __.
6. _P_ __ __ __ __ __ __ transport does NOT REQUIRE energy.
7. A cell placed in an _I_ __ __ __ __ __ __ __ 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 _H_ __ __ __ __ __ __ __ __ __.
9. A CONCENTRATION _G_ __ __ __ __ __ __ __ 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 = _H_ __ __ __ __ __ __ __ __.
11. When molecules move from high to low along a concentration gradient we
say they are moving “_D_ __ __ __” the gradient.
12. The shrinking of a plant cell membrane away from the cell wall when placed in
a hypertonic solution is called _P_ __ __ __ __ __ __ __ __ __ __.
NAME ________________________________
\Describe diffusion:
 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.
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.
_____________
____________
_____________
_____________
____________
_____________
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?
___________________________________________
b. Which way will the glucose go?
___________________________________________
c. Does this require energy?
___________________________________________
d. Is this active or passive transport?
___________________________________________
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? _______________________
b. Does this require energy? ________________________
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?
____________________________
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?
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?