Lab 3

Question 1

Diffusion

Answer 1

The movement of molecules from an area of high concentration [ ] to an area of low concentration [ ] until equilibrium is reached.

Question 2

Osmosis

Answer 2

The diffusion of water molecules through a selectively permeable membrane.
i.e. Water will move across the membrane from a area of of high water [ ] to and area of low water [ ].

Question 3

Semipermeable / selectively permeable membrane

Answer 3

The cell membrane only allows certain molecules to pass through the membrane, and excludes the others.

Question 4

Tonicity

Answer 4

A measure of the solutions ability to change the shape of cells by affecting the cells internal water volume.

Rapid gain of water may cause cell to swell and rupture.
Rapid loss of water may cause cell to shrivel and die.

Question 5

Isotonic

Answer 5

Two solutions that have the same concentration of dissolved particles and water molecules.
A cell in a isotonic solution will maintain its normal shape/volume.

Question 6

Hypotonic

Answer 6

A solution that contains a lesser [ ] of dissolved particles and a greater [ ] of water molecules.

i.e. Water molecules enter the cell faster than they leave and the cell swells/bursts.
The water molecules will flow by osmosis from area of greater water [ ] (outside the cell), to area of lesser water [ ] (inside the cell)

Question 7

Hypertonic

Answer 7

A solution that contains a greater [ ] of dissolved particles and lesser [ ] of water molecules.

i.e. Water molecules leave the cell faster than they enter causing the cell to shrivel/die.
Water will flow by osmosis from area of greater water [ ] (outside the cell), to area of lesser water [ ] (inside the cell)

Question 8

Crenation

Answer 8

When a cell tends to shrink and lose its shape.
Ex. Shrivelling of red blood cells (instead of it’s usual disc shape)

Question 9

Phospholipid bilayer

Answer 9

The living cell membrane

Composed of a double layer of phospholipid molecules with protein molecules floating throughout.

Question 10

Hemolysis

Answer 10

At a certain volume, the cell membrane ruptures and the contents of the RBC are released which leaves only fragments of cell membrane behind

Question 11

Dilute solution

Answer 11

A solution with a very small amount of dissolved particles.

Question 12

Concentrated solution

Answer 12

A solution with a large amount of dissolved particles