communication with other cells (glycoproteins), regulates exchange and reactions between essential substances (carrier proteins), creates attachments within/between cells (fibrous and globular proteins), and isolates cell's contents from external environment (bilayer)
a. Composed of a phospholipid bilayer, polar heads pointed away from each other, and non-polar tails that point towards each other.
b. All phospholipids bond together.
c. Some phospholipids have kinks and those kinks regulate the amount of fluidity in the cell. # of kinks allows the cell to live in different temperature climates.
d. Cholesterol is present in animal membranes stabilizes, affecting and reducing permeability.
e. Small, usually non-polar molecules can diffuse through cell like water, CO₂, O₂, and larger lipid soluble molecules. Ions, amino acids, and sugars cannot easily pass through.
f. Considered to have a fluid mosaic model: the bilayer has the ability to move while the proteins suspend like patchwork. Allows the membrane to be dynamic and structural at the same time. Allows for cellular shape change.