Cell Transport
Cell Bio. & Genetics
Mr. Foster
Cell Transport
• Passive – energy not required to move
material across membrane
– Diffusion – molecules move from high to low
concentration to reach equilibrium
• http://www.indiana.edu/~phys215/lecture/l
ecnotes/lecgraphics/diffusion.gif
Cell Transport
• Passive Transport (cont)• Osmosis – type of diffusion involving H2O molecules
only
• VIDEO LINKhttp://programs.northlandcollege.edu/biology/Bio
logy1111/animations/transport1.html
Cell Transport (cont.)
• Active – Energy required to move materials
across membrane
Low to High concentration
– Ion pumps/Channels- Cl-, Na+, K+, Ca+
– Endocytosis / Exocytosis – membrane forms
pockets to move material
Clicker ?’s 17-20
Endocytosis / Exocytosis
Hypertonic
• A hypertonic solution contains a greater
concentration of impermeable solutes than
the solution on the other side of the
membrane.
H20 in or out
Hypertonic
• If a cell is placed in a hypertonic solution,
there will be a net movement of water out
of the cell until the concentration of
impermeable solutes in the cell equals that
of the hypertonic solution.
Hypotonic
• A hypotonic solution contains a smaller
concentration of impermeable solutes than
the solution on the other side of the
membrane
H20 in or out
Hypotonic
• If a cell is placed in a hypotonic solution,
there will be a net movement of water into
the cell until the concentration of
impermeable solutes in the cell equals that
of the hypotonic solution.
Isotonic
• An isotonic solution contains an equal
concentration of impermeable solutes as
the solution on the other side of the
membrane.
H20 in or out
Isotonic
• If a cell is placed in an isotonic solution,
there will be no net movement of water in
or out of the cell because the
concentration of impermeable solutes in
the cell equals that of the external
environment.
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2. ?
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