Cells in Solutions

Selectively permeable membrane (a.k.a. semi-permeable)

A membrane that only allows certain substance pass through. Small molecules, like Glucose can fit through, large molecules, like starch, can not.

The prefix hypo means . . .

Below, less (the hypodermis is below the dermis; these are layers of your skin)

The prefix iso means . . .

Equal (think isosceles triangle with two equal sides)

The prefix hyper means . . .

Higher, more (think of a hyperactive child; they are more active than the normal child.

Which direction will water move when a cell is placed in a hypotonic solution?

Into the cell (water moves in to dilute the high concentration of water inside the cell)

What will happen to a cell when it is placed in a isotonic solution? (shrink, swell, remain the same?)

It will remain the same Water moves in and out equally, so there is no change in the mass of the cell.

What will happen to a cell when it is placed in a hypertonic solution? (shrink, swell, remain the same?)

It will shrink. (from the water moving out)

What will happen to a cell when it is placed in a hypotonic solution? (shrink, swell, remain the same?)

It will swell. (from the water moving in. Think: in a hypotonic solution, a cell swells like a hippo)

Which direction will water move when a cell is placed in a hypertonic solution?

Out of the cell (water moves out to dilute the high concentration of water outside the cell)

Isotonic Solution

The concentration of solute is equal inside and outside the cell.

Hypertonic Solution

The concentration of solute is higher outside the cell.

Hypotonic Solution

The concentration of solute is lower outside the cell.

Osmosis

The diffusion of water

Equilibrium

The even distribution of molecules after difussion

Solution

The mixture that is created when a solute is evenly distributed within the solvent. Ex) Glucose Solution, Starch Solution

Diffusion

The movement of molecules from a high concentration to a low concentration, until equilibrium is reached

Homeostasis

The process of maintaining a stable internal body condition.

Solute

The substance that is dissolved. Ex) salt, glucose, starch, iodine, Kool-Aid

Solvent

The substance that the solute dissolves in. Water is called the "universal solvent" because it is so good at dissolving things.

Describe what happens to red blood cells in a isotonic solution.

Water is moving in and out equally. The cells retain (keep) their normal shape.

Describe what happens to red blood cells in a hypotonic solution.

Water is moving into the cells causing them to swell. One has even exploded.

Describe what happens to red blood cells in a hypertonic solution.

Water is moving out of the cells causing them to shrink.

Which direction will water move when a cell is placed in an isotonic solution?

Water will move both in and out equally. Movement NEVER stops.