7 Diffusion through a Membrane Cell membraneSolute moves DOWN concentration gradient (HIGH to LOW)
8 Diffusion across a membrane Semipermeable membrane OsmosisDiffusion across a membraneDiffusion of water across a membraneMoves from HIGH water potential (low solute) to LOW water potential (high solute)Semipermeable membrane
9 Diffusion of H2O Across A Membrane High H2O potential Low solute concentrationLow H2O potential High solute concentration
10 Cell in Isotonic Solution 10% NaCL 90% H2OENVIRONMENTCELLNO NET MOVEMENT10% NaCL90% H2OWhat is the direction of water movement?equilibriumThe cell is at _______________.
11 Cell in Hypotonic Solution 10% NaCL 90% H2OCELL20% NaCL80% H2OWhat is the direction of water movement?
12 Cell in Hypertonic Solution 15% NaCL 85% H2OENVIRONMENTCELL5% NaCL95% H2OWhat is the direction of water movement?
19 Passive Transport Simple Diffusion Doesn’t require energy Moves high to low concentrationExample: Oxygen or water diffusing into a cell and carbon dioxide diffusing out.
20 Facilitated diffusion Passive TransportFacilitated diffusionDoesn’t require energyUses transport proteins to move high to low concentrationExamples: Glucose or amino acids moving from blood into a cell.
22 Active Transport Requires energy or ATP Moves materials from LOW to HIGH concentrationAGAINST concentration gradient
23 Active transportExamples: Pumping Na+ (sodium ions) out and K+ (potassium ions) in against strong concentration gradients.Called Na+-K+ Pump
24 Sodium-Potassium Pump 3 Na+ pumped in for every 2 K+ pumped out; creates a membrane potential
25 Exocytosis- moving things out. Moving the “Big Stuff”Exocytosis- moving things out.Molecules are moved out of the cell by vesicles that fuse with the plasma membrane.This is how many hormones are secreted and how nerve cells communicate with one another.
26 ExocytosisExocytic vesicle immediately after fusion with plasma membrane.
27 Moving the “Big Stuff”Large molecules move materials into the cell by one of three forms of endocytosis.
28 Pinocytosis Most common form of endocytosis. Takes in dissolved molecules as a vesicle.
29 Pinocytosis Cell forms an invagination Materials dissolve in water to be brought into cellCalled “Cell Drinking”
30 Example of Pinocytosis mature transport vesiclepinocytic vesicles formingTransport across a capillary cell (blue).
31 Receptor-Mediated Endocytosis Some integral proteins have receptors on their surface to recognize & take in hormones, cholesterol, etc.
35 Phagocytosis - Capture of a Yeast Cell (yellow) by Membrane Extensions of an Immune System Cell (blue)
36 Exocytosis The opposite of endocytosis is exocytosis Exocytosis The opposite of endocytosis is exocytosis. Large molecules that are manufactured in the cell are released through the cell membrane.Inside CellCell environment
40 FROM A LOT to NOT Molecules move _______“where there’s _______” Animatioin from:Molecules move_______“where there’s _______”____“where there’s _______”FROMA LOTtoNOT
41 DIFFUSION across a space Happens anytime there is a __________ in concentration in one place compared to another= ________________________DIFFERENCEConcentration gradient
42 DIFFUSION across a SPACE Molecules move automatically _______ the concentration gradient _______ an area of _______ concentration ____ an area of ________ concentrationEXAMPLESDOWNfromHighertoLowerBlue dye in beaker demo,Someone making popcorn/grilling outStrong perfume,Bad smell in room
43 DIFFUSION across a space Diffusion continues until the concentration is ________________ in space= ________________________equal everywhereEquilibrium
44 Molecules need to move across membranes in cells Image modiified from:
45 Diffusion can happen ________ a _____________ in a cell, too acrossmembrane…as long as membrane will let the molecule _________________pass through
46 SELECTIVELY PERMEABLE (Semi-permeable) Video from:SELECTIVELY PERMEABLE (Semi-permeable)See a movie
47 CELL EXAMPLE:DIFFUSION automatically moves oxygen from HIGHER concentration (in lungs) to a LOWER concentration (in blood)CO2 automatically moves from where there is aHIGHER concentration(in blood) to where thereis a lower concentration(in lungs)
48 BUT…. What if a cell needs to move _____ or ______ molecules? LARGEPOLAR
49 What if cell needs to move a molecule _________ the CONCENTRATION GRADIENT? _______________ AGAINST(LOWER HIGHER)Cell example:Want to put MORE glucoseinto mitochondria when there isalready glucose in thereImage from:
50 What if cell needs to move molecules really _______ What if cell needs to move molecules really _______? (can’t wait for it to diffuse)FASTCell example:Movement of Na + & K+ ionsrequired to sendnerve signals
51 We need a ____ to ____ molecules across cell membranes that _______ across by ___________ WAYHELPcan’t gothemselves
53 Kinds of ________ Transport PASSIVE_____________________________________________________________________DiffusionOsmosisFacilitated Diffusion
54 DIFFUSION across a membrane DIFFERENCEHappens anytime there is a __________ in _____________ on one side of the membrane compared to the otherconcentrationMolecules that move bydiffusion across membranesin cells:______________OXYGENCARBON DIOXIDESee diffusion animation
55 OSMOSIS OSMOSIS DIFFUSION Semi-permeable lower = SPECIAL KIND OF DIFFUSIONIMAGE by RIEDELLOSMOSIS____________See osmosisanimationDIFFUSION__________Movement of molecules across a _________________ membrane from ______ concentration to _____Semi-permeablelowerHigher
57 Facilitated Diffusion _______ proteins help diffusion go faster Carrier
58 FACILITATED DIFFUSION PASSIVENo energy required = __________________Moves _________ concentration gradientfrom _____________________________________________ grab molecule, change shape, and flip to other side (Like a revolving door)Molecules that move this way in cells:_______________________DOWNHIGHER to LOWERMembrane proteinsGLUCOSE
63 Sodium (Na+)- Potassium (K+) Pump Animation from:See a movie about Na+ - K+ pump
64 Sodium-Potassium pump ACTIVE___________ transport(requires energy from ______)Special just for Na+ and K + ionsUses integral ___________________ to move moleculesExamples in nerve cells: Na+ is pumped out of cells at same time K + is taken into cellsATPCarrier Proteins
66 ENDOCYTOSIS Takes substances into cell ACTIVE_____________transport(requires __________ from ______)Uses small membrane sacs called ______________ to carry substancesenergy ATPVESICLES
67 2 KINDS of ENDOCYTOSIS Takes substances into cell If taking in:fluid or small molecules =_________________large particles or whole cells =______________Examples in cells:one celled organisms eat this waywhite blood cells get rid of bacteria this wayPINOCYTOSISPHAGOCYTOSIS
70 PHAGOCYTOSIS Called “Cell Eating” ___________ destroying _______ germs White blood cellgerms___________ destroying _______
71 EXOCYTOSIS Substances released outside of cell ACTIVE__________ transport (requires __________)Substances move in____________Examples in cells:_________ release packaged proteins this wayenergyVESICLESGOLGI
73 GOLGI BODIES USE EXOCYTOSIS Video:GOLGI BODIES USE EXOCYTOSISAnimation from:See a Golgi movie
74 Endocytosis & Exocytosis Videos from:Endocytosis & ExocytosisWatch a video clip about endo/exocytosisChoose Screen/Switch programs to view
75 INSULIN being released by pancreas cells using exocytosis
76 What if there is a difference in concentration but solute molecules can’t move across a membrane? WATER will moveuntil concentrationreaches equilibrium
77 VOCAB_____________ = substance that is dissolved in a solvent to make a solution_____________ = substance in which a solute is dissolvedSOLUTESOLVENTEX:Koolaid powder = soluteWater = solventKoolaid drink = solution
78 Images by Riedell__________________ = mass of a solute in a given volume of solutionCONCENTRATIONMOREThe _______ molecules there are in a given volume the ____________the concentrationGREATER
81 OSMOSIS shrinks GREATER THAN Animation from:OSMOSISSee an animationOSMOSIS 4HYPERTONIC: Concentration outside cell is ____________________ inside cellMore water leaves cell than enters so cell ____________GREATER THANshrinks
82 Cell in Hypertonic Solution 15% NaCL 85% H2OENVIRONMENTCELL5% NaCL95% H2OWhat is the direction of water movement?
83 OSMOSIS Swell and possibly burst LESS THAN Animation from:OSMOSISSee an animation Osmosis3HYPOTONIC: Concentration outside cell is ________________ inside the cell More water enters than leaves cell so cell will ___________________LESS THANSwell and possibly burst
84 Cell in Hypotonic Solution 10% NaCL 90% H2OCELL20% NaCL80% H2OWhat is the direction of water movement?
85 OSMOSIS ISOTONIC: Concentration outside cell __________ EQUALS concentration inside cellWater entering = water leaving so cell _____________________EQUALSSTAYS THE SAME SIZE
86 Cell in Isotonic Solution 10% NaCL 90% H2OENVIRONMENTCELLNO NET MOVEMENT10% NaCL90% H2OWhat is the direction of water movement?equilibriumThe cell is at _______________.
87 NO NET MOVEMENT OF H2O (equal amounts entering & leaving) Isotonic SolutionHypotonic SolutionHypertonic SolutionNO NET MOVEMENT OF H2O (equal amounts entering & leaving)Cell Swells & may burstCell shrivels up