PACK IT UP, MOVE IT OUT...OR IN

SELECTIVELY PERMEABLE OR SEMI- PERMIABLE

• A cell membrane is semi- or selectively permeable.
• This means that it is "selective" or "picky" about what it allows to move across it.

TWO TYPES OF TRANSPORT

• Active Transport- the transport of materials across the cellular membrane that requires energy. (This type of transport is needed when particles are large or when particles are moving from areas of low concentration to high concentration.)
• Passive Transport- the transport of materials across the cellular membrane that does NOT require energy. ( This type of transport occurs when particles are moving from areas with of high concentration to areas of low concentration.)

WHAT IS DIFFUSION AND OSMOSIS?

• Diffusion is the transport of materials over the cell membrane through passive transport.
• Osmosis is the transfer of water across the cell membrane. This is done by passive transport.

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ENDOCYTOSIS VS EXOCYTOSIS

• Endocytosis- part of the cell membrane surrounds materials in a vesicle and carries them INTO the cell to be released inside- using energy. ( Active Transport)
• Exocytosis- part of the cell membrane or Golgi body surrounds materials in a vesicle and carries them OUT of the cell- using energy. (active Transport)

TRANSPORT PROTEINS

• Protein embedded in the cell membrane responsible for "picking up" molecules from the outside or inside of the cell and carrying across the cell membrane using energy. ( Active Transport)