Scribe Post 10/3

What we did in class today

• Finished plasma membrane notes
  


• Completed diffusion, osmosis, and active transport notes

Homework

• Read Lab UP 37-39


• Study for Quiz tomorrow

Diffusion

• 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
  

Osmosis

• 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
  

Osmoregulation

• 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
  

Exocytosis

• remember by: exo sounds like exit



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

Endocytosis

• endo sounds like enter
  


• forms vesicle to enter cell

examples:
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