Download Under what conditions do cells gain or lose water? Molecules Name

Under what conditions do cells gain or lose water?
Molecules
Name
Hypotonic
Solution
Isotonic
Solution
Hypertonic
Solution
Red Blood
Cell: Net
Water
Movement
In/Out
In
Red Blood
Cell:
Appearance
of Cell
Elodea: Net Elodea:
water
Appearance
Movement of Cell
In/Out
Paramecium: Paramecium:
Net
Water Appearance
Movement
of Cell
In/Out
Swell
In
Swell
In
Swell
In/Out
No Change
In/Out
No Change
In/Out
No Change
Out
Shrink
Out
Shrink
Out
Shrink
Question 1: Did water move into the cell or out of the cell while it was surrounded by hypotonic
solution?
-- The water moved into the cell while it was surrounded by hypotonic solution.
Question 2: In which direction did the water move through the cell membrane when the cell was
surrounded by the hypertonic solution?
-- The water moved out of the cell membrane when the cell was surrounded by the hypertonic
solution.
Question 3: Compare and contrast what happens to an animal, a plant, and a Paramecium cell in a
hypotonic, an isotonic, and a hypertonic solution.
-- The hypotonic solution means the solution with the least amount of solute compared to inside the
cell.
-- The hypertonic solution means the solution with the greatest amount of solute compared to inside
the cell.
-- The isotonic solution means the solution of the concentration of solute equal the concentration
inside the cell.
-- when put an animal, a plant, and a Paramecium cell in a hypotonic solution, the water will move
into the cell, and the cell will swell perhaps burst; when put the cells in hypertonic solution, the water
will move out of the cell, and the cell will shrink; when put the cells in isotonic solution, the water will
move in and out in same rate, the cell will not change.
-- No matter what kinds of cells, they all work in same way.
Question 4: Could Elodea or Paramecium from a freshwater lake be expected to survive if transplanted
into the ocean? Explain.
-- the Elodea or Paramecium from a freshwater lake will not survive if transplanted into the ocean.
Because the environment will become the hypertonic solution to the cell, and the water will move out
of the cell, the cell will shrink.
Question 5: If you were to grill a steak, would it be better to put salt on it before or after you cooked
it？ Explain why, in terms of osmosis.
-- It would be better to put salt on it after cooked it.
-- Because if put the salt on it right before cook it, after the salt mix with water, the environment
outside of the meat cell would become hypertonic sulution to the cell. The water in the meat cell
would move out of the cell through the membrance, and the meat would be dry and tough. But if put
the salt on it after cook it, the meat would be juicy.
Question 6: Why does salad become soggy and wilted when the dressing has been on it for a while?
Explain why, in terms of osmosis.
-- Because there are water and salt in the dressing, when they mix with vegetables, the environment
will become the hypertonic solution to the plant cell. The water in the plant cell will move throgh the
membrane to outside, and the plant cell will shrink. So the salad become soggy and wilted.
Question 7: An effective way to kill weeds is to pour salt water on the ground around the plants.
Explain why the weeds die, using the principles discovered in this Virtual Lab.
-- The salt water is the hypertonic solution to the weeds. According to this Virtual Lab,when the plant
cell put into the hypertonic solution, the water in the cell will move out of the membrane, so the plant
cell will shrink. This is the reason the weeds die after pour salt water on the ground around the plants.