passive transport. goals relate concentration gradient, diffusion and equilibrium relate...
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Passive TransportPassive Transport
Goals Goals
Relate concentration gradient, diffusion and Relate concentration gradient, diffusion and equilibriumequilibrium
Predict direction of water movement in and Predict direction of water movement in and out of cellsout of cells
Describe the importance of ion channels in Describe the importance of ion channels in passive transportpassive transport
Identify carrier proteins in facilitated diffusionIdentify carrier proteins in facilitated diffusion
Passive TransportPassive Transport
Random movement across a cell Random movement across a cell membrane that does not require any membrane that does not require any sort of energysort of energy
Passive TransportPassive Transport
How does this happen?----Imagine How does this happen?----Imagine what happens when we place what happens when we place bouncing balls into one room and bouncing balls into one room and then open the door to another room?then open the door to another room?
Passive TransportPassive Transport
Step 1: Imagine many balls bouncing around a Step 1: Imagine many balls bouncing around a single room.single room.
Step 2: Open a door to the adjoining room, Step 2: Open a door to the adjoining room, letting balls out of the room and into the otherletting balls out of the room and into the other
Step 3: Eventually the amount of balls per Step 3: Eventually the amount of balls per room will even outroom will even out
Passive TransportPassive Transport
Concentration gradient-Concentration gradient-A A difference in the concentration of a difference in the concentration of a substance from one spot to anothersubstance from one spot to another
Passive TransportPassive Transport
Equilibrium-Equilibrium-When each side of the When each side of the concentration gradient is equal in concentration gradient is equal in amounts of substancesamounts of substances
Passive TransportPassive Transport
In all solutions, the particles will In all solutions, the particles will move randomly like the balls in the move randomly like the balls in the model.model.
Passive TransportPassive Transport
Once equilibrium is reached, Once equilibrium is reached, particles still move around particles still move around consistently, however we do not see consistently, however we do not see the movement the movement
MovementMovement
Cell membrane (Phospholipid Cell membrane (Phospholipid Bilayer)Bilayer) Selectively PermeableSelectively Permeable Membrane allows materials to dissolve Membrane allows materials to dissolve
throughthrough Nonpolar material repels ions, but Nonpolar material repels ions, but
small molecules can filter throughsmall molecules can filter through
Cell MembraneCell Membrane
Help organisms maintain Help organisms maintain homeostasis by controlling the exit homeostasis by controlling the exit and entrance of materialsand entrance of materials
Passive transport-when organisms Passive transport-when organisms cross the membrane without any cross the membrane without any input of energyinput of energy
1. The activities of a cell depend on the materials that enter and leave the cell. 2. To stay alive, a CELL MUST EXCHANGE Materials such as Food and Waste With Its ENVIRONMENT. 3. These materials must cross the Cell Membrane.
4. Small molecules like WATER, OXYGEN, AND CARBON DIOXIDE can move in and out freely. 5. Large molecules like PROTEINS AND CARBOHYDRATES CANNOT. 6. The Cell Membrane is SEMIPERMEABLE. 7. A SEMIPERMEABLE MEMBRANE OR SELECTIVELY PERMMEABLE ONLY ALLOWS CERTAIN MOLECULES TO PASS THROUGH.
MovementMovement
Diffusion-Diffusion-Movement of particles Movement of particles from an area of high concentration to from an area of high concentration to an area of lower concentrationan area of lower concentration
DiffusionDiffusion
Simplest type of passive transportSimplest type of passive transport Driven by kinetic energy-energy of motionDriven by kinetic energy-energy of motion Rate depends onRate depends on
TemperatureTemperature Diffusion is quicker at high temperaturesDiffusion is quicker at high temperatures
Type of moleculeType of molecule Smaller molecules diffuse fasterSmaller molecules diffuse faster
DiffusionDiffusion
When molecules are dispersed EVENLY, When molecules are dispersed EVENLY, there is no longer any Diffusion because there there is no longer any Diffusion because there is no longer a Concentration Gradient. is no longer a Concentration Gradient.
Diffusion will Eventually cause the Diffusion will Eventually cause the Concentration of molecules to be the SAME Concentration of molecules to be the SAME Throughout the Space the Molecules Occupy. Throughout the Space the Molecules Occupy.
OsmosisOsmosis
OsmosisOsmosis
Osmosis-The Diffusion of water Osmosis-The Diffusion of water from an area of high concentration from an area of high concentration to low concentration across the cell to low concentration across the cell membranemembrane
OsmosisOsmosis
Like any other Diffusing Molecule, Like any other Diffusing Molecule, Water moves DOWN its Water moves DOWN its Concentration Gradient Concentration Gradient
OsmosisOsmosis
OSMOSIS OCCURS IN RESPONSE TO OSMOSIS OCCURS IN RESPONSE TO THE CONCENTRATION OF SOLUTES THE CONCENTRATION OF SOLUTES DISSOLVED IN WATERDISSOLVED IN WATER. .
OsmosisOsmosis
SOLUTES-DISSOLVED SUBSTANCES IN SOLUTES-DISSOLVED SUBSTANCES IN A SOLUTIONA SOLUTION. .
Cytoplasm is Mostly Water containing many Cytoplasm is Mostly Water containing many dissolved solutes. dissolved solutes.
OsmosisOsmosis
No two molecules can occupy the same space No two molecules can occupy the same space at the same time, so if there are more solutes at the same time, so if there are more solutes there is less waterthere is less water
Water Moves from AREAS of LOW Solute Water Moves from AREAS of LOW Solute Concentration to AREAS of HIGH Solute Concentration to AREAS of HIGH Solute Concentration. Concentration.
OsmosisOsmosis
HYPERTONIC SOLUTIONHYPERTONIC SOLUTION- - More Solute then solutionMore Solute then solution Concentration of solute is higher outside the Concentration of solute is higher outside the
cell then it is inside the cellcell then it is inside the cell Water Moves out of the cellWater Moves out of the cell
the cell loses too much water, the cell will shrivel and shrink, it will die
OsmosisOsmosis
IN A IN A HYPOTONIC SOLUTION- HYPOTONIC SOLUTION- Less Solute and more solutionLess Solute and more solution concentration of solute inside the cell is concentration of solute inside the cell is
higher then the fluid out of the cellhigher then the fluid out of the cell water will diffuse into the cellwater will diffuse into the cell
In Hypotonic Solutions, WATER DIFFUSES INTO THE CELL until Equilibrium is established.
OsmosisOsmosis
Animal cells placed in distilled water Animal cells placed in distilled water (Hypotonic Solution) will swell and often (Hypotonic Solution) will swell and often burst because of Osmosis. burst because of Osmosis.
Cytolysis-bursting of cells due to increased Cytolysis-bursting of cells due to increased amounts of water amounts of water
OsmosisOsmosis
Plant Cells do not burst because of their Rigid Plant Cells do not burst because of their Rigid Cell Wall. Cell Wall.
TURGOR PRESSURETURGOR PRESSURE- pressure that Water - pressure that Water molecules exert against the cell wallmolecules exert against the cell wall
OsmosisOsmosis
In Isotonic solutions the inside and outside of In Isotonic solutions the inside and outside of the cells are equalthe cells are equal
How does this relate to cellsHow does this relate to cells
Single cell organisms and sea faring Single cell organisms and sea faring vertebrates have no problems in an isotonic vertebrates have no problems in an isotonic solutionsolution
Many cells function in a Hypotonic Many cells function in a Hypotonic environment, such as Unicellular Freshwater environment, such as Unicellular Freshwater Organisms. Water Constantly Diffuses into Organisms. Water Constantly Diffuses into these Organisms these Organisms
Facilitated DiffusionFacilitated Diffusion
Facilitated DiffusionFacilitated Diffusion
Review-Review- Passive Transport involves no energyPassive Transport involves no energy Occurs down the gradientOccurs down the gradient Diffusion and Osmosis are passiveDiffusion and Osmosis are passive
Facilitated DiffusionFacilitated Diffusion
Molecules that cannot cross by Molecules that cannot cross by passive transport are passive transport are CARRIEDCARRIED across by across by CARRIER PROTEINSCARRIER PROTEINS EMBEDDED IN the Cell Membrane. EMBEDDED IN the Cell Membrane.
Facilitated DiffusionFacilitated Diffusion
1. Carrier Proteins 1. Carrier Proteins CHANGE SHAPECHANGE SHAPE when when Molecules ATTACH to them. Molecules ATTACH to them.
2. The Carrier Protein then releases the 2. The Carrier Protein then releases the molecule and returns to its original shapemolecule and returns to its original shape
Facilitated DiffusionFacilitated Diffusion
Facilitated Diffusion-THE USE OF Facilitated Diffusion-THE USE OF CARRIER PROTEINSCARRIER PROTEINS
Facilitated Diffusion can help Facilitated Diffusion can help substances move Either INTO or substances move Either INTO or OUT of a CellOUT of a Cell
Facilitated DiffusionFacilitated Diffusion
Example- When cells transport Example- When cells transport Glucose into the Cell. Glucose into the Cell.
Cells depend on Glucose for much of Cells depend on Glucose for much of their Energy Needs. their Energy Needs.
PassivePassive
Facilitated DiffusionFacilitated Diffusion
Ion Channels-Ion Channels-Small passageways across the Small passageways across the membrane which ions can diffusemembrane which ions can diffuse
Sodium (Na+) and Potassium (K+)Sodium (Na+) and Potassium (K+)
Facilitated DiffusionFacilitated Diffusion
Some ION CHANNELS are always Some ION CHANNELS are always open. open.
Others have "Gates" that open to Others have "Gates" that open to allow ions to pass or close to stop allow ions to pass or close to stop their passage. their passage.
Facilitated DiffusionFacilitated Diffusion
Gates are dependant upon the environment of Gates are dependant upon the environment of the cellthe cell
Three kinds of Stimuli that may open or close Three kinds of Stimuli that may open or close the Gates: the Gates: Stretching of the Cell MembraneStretching of the Cell Membrane Electrical SignalsElectrical Signals Chemicals in the Cytosol or External EnvironmentChemicals in the Cytosol or External Environment
Active TransportActive Transport
GoalsGoals
Compare active transport with passive Compare active transport with passive transporttransport
Describe the importance of the sodium-Describe the importance of the sodium-potassium pumppotassium pump
Distinguish between endocytosis and Distinguish between endocytosis and exocytosisexocytosis
Identify three ways that receptor proteins can Identify three ways that receptor proteins can change the activity of the cellchange the activity of the cell
Active TransportActive Transport
ACTIVE TRANSPORTACTIVE TRANSPORT-When cells use -When cells use energy to move materials from an area of low energy to move materials from an area of low concentration to high concentrationconcentration to high concentration
Active Transport Active Transport often involves often involves CARRIER CARRIER PROTEINSPROTEINS like like those in Facilitated those in Facilitated Diffusion Diffusion
Cell Membrane PumpsCell Membrane Pumps
Cell Membrane Pumps-Carrier Cell Membrane Pumps-Carrier proteins that act to move ions across proteins that act to move ions across the membrane during active transportthe membrane during active transport
Cell Membrane PumpsCell Membrane Pumps
IMPORTANTIMPORTANT in in MAINTAINING ION MAINTAINING ION CONCENTRATION IN CELLS AND CONCENTRATION IN CELLS AND BETWEEN CELLS.BETWEEN CELLS.
Cell Membrane PumpsCell Membrane Pumps
SODIUM-POTASSIUM PUMPS-SODIUM-POTASSIUM PUMPS- IMPORTANT FOR MUSCLE IMPORTANT FOR MUSCLE
CONTRACTIONS, CONTRACTIONS, TRANSMISSION OF NERVE IMPULSES TRANSMISSION OF NERVE IMPULSES THE ABSORPTION OF NUTRIENTS THE ABSORPTION OF NUTRIENTS
Cell Membrane PumpsCell Membrane Pumps
SODIUM-POTASSIUM PUMPSSODIUM-POTASSIUM PUMPS -ANIMAL -ANIMAL CELLS PUMP CELLS PUMP SODIUM IONS OUTSODIUM IONS OUT, AND , AND POTASSIUM INPOTASSIUM IN
Cell Membrane PumpsCell Membrane Pumps
In Plants, ACTIVE TRANSPORT enables In Plants, ACTIVE TRANSPORT enables roots to absorb nutrients from the soil roots to absorb nutrients from the soil
Plant Nutrients are more concentrated inside Plant Nutrients are more concentrated inside the roots than in the surrounding soil the roots than in the surrounding soil
WITHOUT ACTIVE TRANSPORT, WITHOUT ACTIVE TRANSPORT, NUTRIENTS would DIFFUSE OUT OF THE NUTRIENTS would DIFFUSE OUT OF THE ROOTS ROOTS
Why does this happenWhy does this happen
Takes away toxic sodium ions from the cellTakes away toxic sodium ions from the cell
Maintains concentration gradientMaintains concentration gradient
Bulk Transport-Endocytosis and Bulk Transport-Endocytosis and ExocytosisExocytosis
TransportTransport
Bulk Transport-COMPLEX PROTEINS,that Bulk Transport-COMPLEX PROTEINS,that are too LARGE to cross the Cell Membrane, are too LARGE to cross the Cell Membrane, travel through the membrane via bulk transporttravel through the membrane via bulk transport
4 Types of bulk transport4 Types of bulk transport EndocytosisEndocytosis ExocytosisExocytosis PinocytosisPinocytosis PhagocytosisPhagocytosis
EndocytosisEndocytosis
During During ENDOCYTOSISENDOCYTOSIS the Cell the Cell Membrane Folds into a POUCH that Encloses Membrane Folds into a POUCH that Encloses the Particles the Particles
The Pouch pinches off INSIDE the Cell to The Pouch pinches off INSIDE the Cell to form a form a VESICLEVESICLE The VESICLE can then The VESICLE can then fuse with other Organelles (LYSOSOMES) or fuse with other Organelles (LYSOSOMES) or Release its contents into the Cytoplasm. Release its contents into the Cytoplasm.
PINOCYTOSIS AND PHAGOCYTOSIS PINOCYTOSIS AND PHAGOCYTOSIS ARE TWO TYPES ON ENDOCYTOSISARE TWO TYPES ON ENDOCYTOSIS PINOCYTOSISPINOCYTOSIS IS SOMETIMES CALLED IS SOMETIMES CALLED
"CELL DRINKING"CELL DRINKING PHAGOCYTOSISPHAGOCYTOSIS - -"CELL EATING""CELL EATING"
ExocytosisExocytosis
EXOCYTOSISEXOCYTOSIS IS THE OPPOSITE OR IS THE OPPOSITE OR REVERSE OF ENDOCYTOSIS REVERSE OF ENDOCYTOSIS
Exocytosis is when waste and cell products Exocytosis is when waste and cell products leave the cellleave the cell