Movements Into and Out of the Cell

Passive Transport

Diffusion, facilitated diffusion, and osmosis (requires no energy)

Active Transport

Active transport, endocytosis, and exocytosis (requires energy to move substances from low to high concentration)

Tonicity

Describes how osmosis causes water to move across the cell membrane due to differences in solute concentration; water moves toward the area with the higher solute concentration

Tonicity

Describes how osmosis causes water to move across the cell membrane due to differences in solute concentration; water moves toward the area with the higher solute concentration

Isotonic

Equal salute concentration inside & outside the cell

Hypertonic

Lower solute concentration outside the cell

Hypertonic

Lower solute concentration outside the cell

Facilitated diffusion

Molecules that can't pass through the membrane directly pass through transport proteins (ion channels or carrier proteins)

Osmosis

Diffusion of water across the membrane on channel proteins called aquaporins

Osmotic pressure

The pressure needed to lift a volume of water

Protein pumps

Transport proteins (pumps) use ATP to move molecules from low concentration to high concentration

Endocytosis

The process where a cell brings material inside by wrapping it in its membrane to form a vesicle

Exocytosis

Vesicles fuse with the cell membrane to release materials out of the cell