Monday, October 3, 2011

Scribe Post 10/3

What we did in class today

  • Finished plasma membrane notes

  • Completed diffusion, osmosis, and active transport notes


  • Read Lab UP 37-39

  • Study for Quiz tomorrow

  • When molecules of a substance, or solute, move from area of high concentration to low concentration

  • must have selectively permeable membrane

  • Things that fit through the pores will go to the other side of the membrane to create equal concentration

  • Equal concentration is called equilibrium


  • Movement of water from low concentration to high concentration

  • Water moves to the side of the membrane with higher concentration of solute

  • This helps create an equal density on each side

  • The solute does not move because it is too large to fit through the membrane

  • When density is equal, it has reached equilibrium

Hypertonic Solution

  • When the outside of a cell has a higher concentration of solute than the cell

  • The water moves out of the cell to dilute the outer part with the higher concentration

  • This causes the cell to shrivel

  • In plant cells it is called plasmolysis

  • Cells are not usable when this happens because of lack of water

Hypotonic Solution

  • When a cell contains a higher concentration of solute than the outer part

  • Water moves into the cell to balance the concentration

  • This is bad in animals cells and causes them to burst: Lysing

  • This is very good in plant cells and fills the vacuole: Turgid

Isotonic Solution

  • When there are equal amounts of solute concentration in the cell and outside of it

  • Animals need this to function

  • Plants wilt when this happens

  • Water moves in and out of the cell to keep balance


  • Controlling water balance

  • happens in cells constantly

Active Transport

  • uses energy

  • energy in form of ATP

  • does not follow same rules as diffusion

  • works from low concentration to high, against concentration gradient


  • remember by: exo sounds like exit

  • removes contents from cell when vesicle fuses with the plasma membrane


  • endo sounds like enter

  • forms vesicle to enter cell

Phagocytosis- "cell eating" non specific

  • Pinocytosis- "cell drinking" non specific

  • Receptor mediated- external molecules bond to specific receptor proteins, specific

Don't forget to study!

Sorry it won't let me put pictures in

Next Scribe: Charles

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