Name ___________________________________________ Period __________ Date ______________
Cell Transport -– Chapter 7 Sections 3 & 4
• Cell Membrane
• _________________________what enters and leaves the cell
• Cell membrane is surrounded by __________________
• Phospholipid bilayer
• Lipid bilayer
• Forms by itself in water
• Proteins attached
• __________________
• __________________
• ____________________________
• Diffusion in cells
• When small __________________ diffuse in and out of the cell to reach
___________________________ on both side of the membrane
• Passive Transport
• Does _____________ require any __________________
• Happens ____________________________________
• __________________ may be used in cell membrane
• This type of transport moves from an area of __________________
concentration to __________________concentration
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• Diffusion
• Type of __________________ transport
• When __________________ move from an area of __________________
concentration to an area of __________________ concentration until
equilibrium is met
• Concentration
• The amount of dissolved __________________ in a __________________
• Molecules will move to an area ______________ concentrated
• Molecules diffuse through the cell membrane of cells
• Concentration gradient
• The _______________________ in concentration in a solution between a
cell and its surroundings
• No gradient - __________________ distribution
• Concentration to the __________________
2
• Increase Rate of Diffusion
• Temperature
• Molecules move __________________ in __________________
temperatures
• Pressure
• Increasing pressure also _____________________ rate of diffusion
• Equilibrium
• This occurs when there is _____________________ concentration
gradient
• Molecules are _____________________ dispersed but still continue to
move randomly
• Osmosis
• Diffusion of _____________________ across a biological membrane
• From an area of ___________________ concentration to ___________
concentration of WATER
• Cells are surrounded by water and are filled with water
• Water can move freely through the _______________________________
3
• Direction of Osmosis
• Osmotic Pressure
• Net movement of _____________________ into cells
• Determined by _____________________ concentration
• Osmosis – hypertonic
• _____________________ concentration of solute in solution
• Ex: a cell in salt water
• If molecules are too large to fit through cell membrane or protein
channels
• _____________________ will diffuse ______________ of the cell to reach
equilibrium
• Cell _____________________
4
• Osmosis – hypotonic
• _____________________ concentration of solute in solution
• Ex: a cell in pure water
• If molecules are too large to fit through cell membrane or protein
channels
• _____________________ will diffuse ______________ the cell to reach
equilibrium
• Cell _____________________ - may burst!
• Osmosis – Isotonic
• _____________________ concentration of solute in solution
• If molecules are too large to fit through cell membrane or protein
channels
• _____________________ will diffuse _________ ___________ ___________of the
cell to maintain equilibrium
• Facilitated Diffusion
• When the cell membrane has _____________________ ____________________
where materials are transported in or out of cell
• ___________ energy needed for this process
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• Active Transport
• ____________________ concentration gradient
• From an area of __________________ concentration to an area of
_________________ concentration
• Requires cell energy (___________) because you’re going
____________________ concentration gradient
• __________________ ___________________ embedded in cell membrane
• Gated channels
• ________________ energy to open
• Protein changes __________________ when energy is used
• Sodium/Potassium Pump
• Step 1: 3 Na+ ions bind to ___________________ __________________
• Step 2: ______ binds to carrier protein and changes __________________
allowing Na+ to move ___________ of the cell
• Step 3: 2 K+ ions move ___________ carrier protein
• Step 4: ___________ binds to carrier protein and changes _____________
allowing K+ to move __________ the cell
6
• Movement in Vesicles
• Endocytosis - _______________ the cell
• Cell membrane is used to create a vesicle around particles
• Phagocytosis
• ______________________ ingestion
• Pinocytosis
• _____________________ ingestion
• Exocytosis - _____________ of the cell
• Vesicles created in the cell fuse with cell membrane and
release particles/liquids
• Known as bulk transport
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