1. Copy and answer the following EQ into your science journal.
Biology February 24, 2014
Copy and answer the following EQ into your science journal.
EQ: How does the structure of the cell membrane aid in its functions of equilibrium?
It helps cells to maintain homeostasis by controlling what is allowed in and out of the cell.

2. Word of the Day Semipermeable
A barrier that permits the passage of some substances but not others.

3. Here is what is going on this week
Your workbook, Ch 7 pp is due today!
Prefix/Suffix quiz part 2 on Friday
Complete the lab in your workbook pp

6. Tonicity
Tonicity is a measure of the osmotic pressure gradient of two solutions separated by a semipermeable  membrane

8. Spraying air freshener in a room
Diffusion is the movement of molecules from a high concentration to a low concentration.
Examples-
Spraying air freshener in a room
The odour of food cooking diffuses throughout the kitchen and spreads into the next room.

9. Osmosis- It is the diffusion of water through a semipermeable membrane from a more dilute solution to a more concentrated solution.
Examples:
Absorption of water by plant roots.
Reabsorption of water by the nephron in kidneys
Absorption of water by the alimentary canal — stomach, small intestine and the colon.

10. Equilibrium
To regulate internal conditions in order to stay healthy and functioning, regardless of the outside changing conditions.

11. There are 3 types of situations in which this could vary:
Hypotonic Isotonic Hypertonic

12. There are 3 types of situations in which this could vary:
1. Hypertonic
In HYPERTONIC solutions, water moves out of the cell.
Hypertonicity causes cells to shrink.
Plants cells lose water and start to wilt.
The process of water moving out of a cell is called plasmolysis.
More H2O moves out of the cell.

13. 2. Isotonic Water DOES or DOES NOT stop moving.
Cells reach a point called Dynamic Equilibrium in isotonic solutions.
Equal amounts of water are found inside and outside of the cell.
H2O moves in and out of the cell equally.

14. 3. Hypotonic In HYPOTONIC solutions, water moves into a cell.
Animal cells increase in size and burst or lyse in these solutions
Bursting of cells is called cytolysis.
Plant cells need this tonicity to be at homeostasis.
Turgor pressure results from water inside a plant cell pushing the cell membrane out against the plant’s cell wall.
More H2O moves into of the cell.

15. Cells in Solution Models
Each cell has a 10%, or 6% NaCl (salt) solution in an ENVIRONMENT with either a 3%, 10% or15% salt solution.
COLOR the cell yellow and the environment light blue.
Using RED, draw arrows showing the direction of movement of water into or out of the cell.
15% NaCl
10% NaCl