Science

Permeability:

   The permeability of a membrane depends on what it allows through.

Plant and animal cells are both considered selectively permeable because they allow some substances to enter and leave the cell

Solutions:

A solution is a mixture in which molecules of one substance are evenly distributed within another substance.

Solutes are the smaller components (particles) dissolved into a solvent. A    solvent is a substance that dissolves a solute.

 Contraction refers to the amount of a substance in a defined space.

 Concentration gradients are how cells feel ¨thirst¨ and ¨hunger¨.

There are two main types of cell transport, passive trans and active transport.

What will the test look like?

-need to learn 8 organelles

-study plant and animal cells 

-osmosis and Cellular transport (mostly cell transport)

-Remember real-life examples of diffusion and osmosis

-talk about the gummy bear experiment on the test

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Hypertonic Solution 

-Hypertonic is a high concentration of solute outside the cell

-The concentration of solute is higher on the outside of the cell membrane.

-If too much water moves out of the cell, it may shrivel up and die.

Hypotonic Solution

-The concentration of solute is higher on the inside of the cell.

-Water moves from the solution into the cell.

Water moves into the cell by osmosis.

-This causes the cell to increase in size. If too much water moves into the cell it may burst

Isotonic Solution

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

This cell is in equilibrium.

Water moves across the membrane in both directions at the same rate.