Moving Cellular Material Chapter 2, Lesson 3

Membranes Control the movement of materials in and out of cell. – Semipermeable – only certain substances can pass through. – There are many different ways for a substance to pass through the membrane. Process depends on the physical and chemical properties of the substance.

Passive Transport The movement of substances through a cell membrane – No energy – Usually small molecules (O 2 and CO 2 ) – Depends on the amount of substances on each side of the membrane.

Diffusion The movement of substances from an area of higher concentration to an area of lower concentration.

Passive Transport - Osmosis The diffusion of water molecules through a selectively permeable membrane. (No energy required) Red Blood Cells

Facilitated Diffusion When molecules pass through a cell membrane using special proteins called transport proteins.

Active Transport The movement of materials through a cell membrane using energy. (Moves from low to high concentration)

Endocytosis The process during which a cell takes in a substance by surrounding it with the cell membrane.

Exocytosis The process during which a cell’s vesicles release their contents outside the cell.