Cell Membrane

Fluid mosaic:
model mixed composition of phospholipids, glycolipds, sterols and proteins.

Adhesion Protein:
help the cell adhere to another or to a protein.

Communication Protein: 
match up with identical proteins in the plasma membrane of an adjoining cell.

Receptor Protein: 

 proteins docks for hormones that cause target cells to change their activities.

Recognition  Protein:
proteins identify a cell as nonself or self.

Passive transporter:
movement of particles across the cell membrane without an imput of energy.

Active transpoter:
movement of particles across the cell membrane with an imput of energy.

Difussion:
 net movement of mocecules or ions down a concentration gradient.

Electric gradient:
 a difference in electric charge between adjoining regions.

Pressure gradient:
 a difference in pressure exerted per unit volume (area) between two adjoining regions.

Concentration gradient:
difference in the number per unit volume of molecules of a substance between adjoining regions.

Hypotonic:
 solution with lower solutes.

Hypertonic:
 solution with more solutes.

Isotonic:
solutions that show no net osmotic movement.

Hydrastatic Pressure:
furgur pressure exerted by any volume of fluids.

Osmotic Presurre:
measure of tending of water to follows its water concentration gradient and move into that fluid.

Osmosis:
diflusion of  water across a selectively permeable membrane, to a region where the water concentration is lower.

Endocytosis:
small patch of plasma membrane ballons inward and pinches off inside the cytoplasm.

Exocytosis:
a vesicle moves to the cell surface, and then the protein-studded lipid bilager of its membrane tuses with the plasma membrane.

Phagocytosis:
common endocytic pathways.