Download Passive Transport – No energy required for these processes to

Objective: Describe how materials move into and out of the cell in the processes of
osmosis, diffusion and active transport.
Passive Transport – No energy required for these processes to occur.
Diffusion: movement of molecules (for instance, salt or sugar) from an area of
high concentration of those molecules to an area of low concentration.
Osmosis: movement of water to move from an area of higher concentration of
solute molecules concentration (example: salty water) to an area of lower solute
molecule concentration (example: less salty, or plain
water) across a semipermeable membrane.
Active Transport - The cell must use energy to either remove the substance from
the cell or to bring more of it into the cell.
For molecules that are too large to actively transport through the cell membrane,
endocytosis and exocytosis are used.
Endocytosis: the cell membrane surrounds and encloses molecules outside the
cell, then detaches from the cell membrane and is transported into the cell.
Exocytosis: vesicles inside the cell merge with the cell membrane and the
contents of the vesicles are released outside the cell.