Date post: | 18-Jan-2018 |
Category: |
Documents |
Upload: | meryl-carr |
View: | 220 times |
Download: | 0 times |
Cell TransportCell TransportLecture #17Lecture #17
Ms. DayMs. DayHonors BiologyHonors Biology
Cell TransportMeans moving things INTO and OUT of the cell
Cells need to take in Food, gases, waterGet rid of waste productsRelease hormones and enzyme
REVIEW…REVIEW…Permeability and Cell TransportPermeability and Cell Transport
Hydrophobic (non polar) moleculesAre lipid soluble (can dissolve) can pass through membrane easily
Ex: CO2, O2
Hydrophilic (Polar) moleculesAre NOT lipid soluble (can’t dissolve)
Lipid INsolubleDo not cross membrane easily
Ex: Na+, Cl- , Glucose/other polar or charged things
Types of Cellular Transport Passive Transport
cell do NOT use energy1. Diffusion/Osmosis2. Facilitated Diffusion
Active Transportcell DOES use energy
1. Protein Pumps2. Endocytosis3. Exocytosis
high
low
This is going to be hard!
high
low
Weee!
Types of Passive Transport
DiffusionDiffusion= molecules (of ANYANY substance) move from area of HIGH [ ] to lower [ ] A “net” movement
Ex: Perfume, a fart , tea, food coloring in water
http://www.indiana.edu/~phys215/lecture/lecnotes/lecgraphics/diffusion2.gif
http://highered.mcgraw-hill.com/sites/0072495855/student_view0/chapter2/animation__how_diffusion_works.html
DIFFUSION DIFFUSION Molecules move DOWN
its OWNOWN concentration gradient
difference in amount of a substance from one area to another
No chemical work (ATP energy) is used
Substances diffuse down their Substances diffuse down their OWN concentration gradientOWN concentration gradient
Net diffusion
Net diffusion
Net diffusion
Net diffusion Equilibrium
Equilibrium
Effects of Osmosis on Effects of Osmosis on Water BalanceWater Balance
Osmosis Diffusion of
waterwater across a semipermeablsemipermeable membranee membraneWater molecules Water molecules
move from MORE move from MORE water to LESS water to LESS waterwater
3 Different Types of Solutions3 Different Types of Solutions** compare solutions OUTSIDE cell to inside cell** compare solutions OUTSIDE cell to inside cell
1. Isotonic solutionAmount of solutes and water is the
same outside cell as inside the cell“iso-” means “same”
There will be NONO net movement of water
Cell does not change in size
ISOTONIC SOLUTION
Result: Water moves equally in both directions and the cell remains same size! (Dynamic
Equilibrium)
2. Hypertonic solutionHypertonic solution Amount of solutes is greater
outside than inside the cell “hyper” means more
high [solute]
The cell will lose water and shrivel or wilt
HYPERTONIC SOLUTION
Result: Water moves from inside the cell into the solution: Cell shrinks!
3.3. Hypotonic solutionHypotonic solutionAmount of solutes is less
outside than inside the cell“hypo” means “less”
• low [solute]Think: Hypo- sounds like
hippo…hippos are big & round; cells in hypotonic solutions get big & roundAlso, think “hypo” is “low” meaning
“low” solutes SURROUNDING cell The cell will gain water and swell
(and maybe burst)
“Hypo” is LOW!!!
HYP0TONIC SOLUTION
Result: Water moves from the solution to inside the cell): Cell Swells and might burst
http://highered.mcgraw-hill.com/sites/0072495855/student_view0/chapter2/animation__how_osmosis_works.html
• Osmosis Animations for
isotonic, hypertonic, and hypotonic
solutions
REVIEW…Types of Passive Transport
#1 #1 Passive TransportDOES NOT require ATP energy Moves DOWN (WITH) [ ] gradient Kinetic energy drives movementKinetic energy drives movement
#2 #2 Active TransportDOES require chemical energy (Ex: ATP)
Moves AGAINST its [ ] gradient
2 Types of PASSIVE TRANSPORT
2 Types of PASSIVE TRANSPORT2. FACILITATED DIFFUSION. FACILITATED DIFFUSIONneeds a little “help”needs a little “help”Uses help of Uses help of channel or carrier channel or carrier
proteinsproteins GOES DOWN CONCENTRATION GRADIENT (no ATP needed)
Moves Moves POLARPOLAR molecules molecules can can NOT NOT easily pass through easily pass through HYDROPHOBIC region of membrane. HYDROPHOBIC region of membrane. Example: ions, smaller polar molecules (ex: Example: ions, smaller polar molecules (ex:
sugar)sugar)
Aquaporinswater is polar but very
smallIt can pass easily through
membrane uses aquaporins Oh…now
I get it!EXTRACELLULARFLUID
AQUAPORINChannel protein
Water CYTOPLASM
Channel proteins-Provide “tunnels”
EXTRACELLULARFLUID
Channel proteinSolute
CYTOPLASM
A channel protein (purple) has a channel through which water molecules or a specific solute can pass.
(a)
• Channel Proteins animations
Carrier proteins-Undergo a subtle change in shape “carry” solute across the membrane
Carrier protein Solute
2 Types of Passive Transport
Active transportActive transportUses energyenergy Moves solutes against
their [ ] gradients across the cell membraneEnergyEnergy required
usually ATPATPCarrier proteinsCarrier proteins are used…
NEVER channel proteinsEx: protein pumps
Passive vs. Active Passive vs. Active TransportTransport
Figure 7.17
Another type of transport = Bulk Another type of transport = Bulk TransportTransport
Occurs by exocytosisexocytosis and endocytosisendocytosis
BOTH MOVE “BIG” BOTH MOVE “BIG” AMOUNTS OF STUFF in OR AMOUNTS OF STUFF in OR
out OF THE CELLout OF THE CELL
ExoExocytosiscytosisIn exocytosisexocytosis
Transport vesicles move to the plasma membrane, fuse with it, and release their contents
“exo-” means “exit”Ex: hormone excretion; nerve cells and transmitters; removal
of wastes
EndoEndocytosiscytosisIn endocytosisendocytosis
Cell takes in molecules by forming new vesicles from the plasma membrane
“endo-” means “enter”
2 types of Endocytosis2 types of Endocytosis1. Phagocytosis 1. Phagocytosis
“cell eating” Cell engulfs SOLIDS
into vesicle & “digests” it
2. Pinocytosis2. Pinocytosis “cell drinking” Cell engulfs LIQUIDS
into vesicle & “digests” it
http://highered.mcgraw-hill.com/sites/0072495855/student_view0/chapter2/animation__phagocytosis.html
Endocytosis and Exocytosis Animations
http://highered.mcgraw-hill.com/sites/0072437316/student_view0/chapter6/animations.html#
REVIEW ANIMATIONS
http://www.northland.cc.mn.us/biology/Biology1111/animations/passive3.swfExcellent Review all Passive
(simple/facilitated diffusion) and Active Transport No verbal explanation…you have to read the
tutorial!