cell transport

fluid mosaic model explains the plasma membrane as being made of:

two layers of phospholipids with cholesterol in between

in animal cell membranes, cholesterol:

keeps phospholipids from packing too tightly together

the majority of a cell membranes functions such as a transport and acting as enzymes are carried out by:

proteins

when water diffuses in and out of cell (in & out)

isotonic

when more water leaves the cell than enters (out)

hypertonic

more water enters the cell than leaves the cell (in)

hypotonic

hypotonic

swells

hypertonic

shrinks