regulates what enters and leaves the cell and also protects (barrier) and supports the cell
most prokaryotes and plant cells produce a strong supporting layer around the membrane
composition of cell membranes is a double layered sheet; gives cell membranes a flexible structure and forms a strong barrier between the cell and its surroundings
selectivley permeable membranes
meaning that some substances can pass across them and others cannot
fluid mosaic model
within the cell membrane, proteins and other molecules are embedded in the lipid bilayer and can move around and float among the lipids.
a single, large vacuole filled with liquid the pressure of this vacuole increases its rigidity- help plants support heavy structures such as leaves and flowers.
found in some unicellular organisms and in some animals; contract rhythmically- move water in and out- help the organism to move