Moving Cellular Materials

Cell Membranes

Selectively permeable Allow only some things to enter and leave.

Passive Transport

Movement of material through the membrane without using energy.

Types of Passive Transport

Diffusion Random movement of particles from areas

of more to areas of less. Equilibrium – equal particles in each area.

Types of Passive Transport

Osmosis The diffusion of water through the cell

membrane. Example: Plants

Types of Passive Transport

Facilitated Diffusion Movement of materials through a transport

protein located in the membrane.

Active Transport

Moving materials through a cell membrane with the use of energy. Requires transport proteins.

Movement of Very Large Particles

Endocytosis Cell membrane surrounds the particle. Section of the membrane pinches off to

form a vesicle.

Movement of Very Large Particles

Exocytosis Opposite process as endocytosis. Contents of the vesicle are released

outside the membrane.