plasma membrane structure- blue

barrier

cell membranes separate the cell from the extracellular environment and provide the cell with its fundamental structure

controlling movement

the membranes are semipermeable, which means that they will allow certain molecules to enter/exit, while others are unable to do so. molecules and ions can cross the cell surface membrane through either diffusion, osmosis, or active transport

cell signaling

hormones bind to complementary receptors on the plasma membrane of target cells

cell recognition

plasma membranes have structures on them which allow the cell to be recognized by other cells(like immune system cells)

receptor proteins

bind to external chemicals in order to regulate processes within the cell

carbohydrate chains

provide a fingerprint for the cell, so it can be recognized by other cells

recognition proteins

provide a fingerprint for the cell, so it can be recognized for other cells

cholesterol

helps the membrane retain its flexibility

transport proteins

provide a passageway for molecules to travel into and out of the cell

membrane enzymes

accelerate intracellular and extracellular reactions on the plasma membrane