anatomy and physiology cell transport. types of transport diffusion characteristics –particles...
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Types of TransportDiffusion
• Characteristics– Particles move from an area of high
concentration to an area of low concentration.
– Moves “down” or “with” the concentration gradient. (difference in concentration)
– Does not require energy.
Types of Transport
• Factors effecting the rate of diffusion– TemperatureTemperature - as temperature
increase, rate of diffusion increases.– PressurePressure - as pressure increases, rate
of diffusion increases.– Steepness of the concentration Steepness of the concentration
gradientgradient - - the steeper the gradient, the faster the rate of diffusion.
Types of Transport
• Diffusion will continue until dynamic equilibrium is reached.
• Dynamic equilibriumDynamic equilibrium - - continuous movement of particles, but no overall concentration change. (Everything is equally distributed).
Type of TransportOsmosis
• Characteristics– Movement of
water across a cell membrane.
– Cell has no control over movement of water. It continues to move until [inside] = [outside].
[ ] =concentration
AS Biology, Cell membranes and Transport
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Osmosis
Cell membrane partially permeable.
Inside cell Outside cell
VERY High concentration of water molecules.
VERY Low concentrationof water molecules.
Sugar molecule
DILUTE SOLUTIONCONCENTRATED SOLUTION
AS Biology, Cell membranes and Transport
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Osmosis
Cell membrane partially permeable.
Inside cell Outside cellHigh conc. of water molecules.
Low conc. of water molecules.
OSMOSIS
AS Biology, Cell membranes and Transport
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Osmosis
Cell membrane partially permeable.
Inside cell Outside cell
OSMOSIS
EQUILIBRIUM. Equal water concentration on each side. Equal water potential has been reached. There is no net movement of water – water moves in and out of cell at the same rate.
What is a solution?
2 Parts:
•Solvent – Usually a liquid like water•Solute – Usually a solid such as sugar, salt
Isotonic SolutionIsotonic: The concentration of solutes in the solution is equal to the concentration of solutes inside the cell.
ISO = THE SAME
Result: Water moves equally in both directions and the cell remains same size! (Dynamic Equilibrium)
• Osmosis Animations for
isotonic, hypertonic, and hypotonic
solutions
Osmosis - Types of Osmosis - Types of SolutionsSolutions
IsotonicIsotonic• [water inside]
= [water outside]
• Dynamic equilibrium reached immediately.
Normal Red blood cells
Hypotonic SolutionHypotonic: The solution has a lower concentration of solutes and a higher concentration of water than inside the cell. (Low solute (HYPO); High water)
Result: Water moves from the solution to inside the cell): Cell Swells and bursts open (cytolysis)!
• Osmosis Animations for
isotonic, hypertonic, and hypotonic
solutions
Osmosis - Types of Osmosis - Types of SolutionsSolutions
HypotonicHypotonic
• [water inside] < [water outside]
• Solutes are higher inside the cell.
• Water flows in, cell swells.
• Cell could burst if water flow continues.
Swollen red blood cells
Hypertonic Solution
Hypertonic: The solution has a higher concentration of solutes and a lower concentration of water than inside the cell. (High solute (HYPER); Low water)
Result: Water moves from inside the cell into the solution: Cell shrinks (Plasmolysis)!
• Osmosis Animations for
isotonic, hypertonic, and hypotonic
solutions
shrinks
Osmosis - Types of Osmosis - Types of SolutionsSolutions
HypertonicHypertonic
• [water inside] > [water outside].
• Solutes are higher outside the cell.
• Water leaves the cell, cell shrinks.
Dehydrated red blood cells
Types of transport
Passive vs. Active Transport
• Passive - no energy required
• Active - energy required
Types of Cellular Transport
• Passive Transport cell doesn’t use energy
1. Diffusion2. Facilitated Diffusion3. Osmosis
• Active Transportcell does use energy
1. Protein Pumps2. Endocytosis3. Exocytosis
high
low
This is gonna
be hard work!!
high
low
Weeee!!!
•Animations of Active Transport & Passive
Transport
Types of Transport
• Passive TransportPassive Transport– Movement across
a membrane by diffusion.
– Facilitated diffusion - moves down the concentration gradient with the aid of a protein molecule.• Most glucose
moves this way
2. Facilitated diffusion: diffusion of specific particles through transport/carrier proteins found in the membrane a.Transport Proteins are
specific – they “select” only certain molecules to cross the membrane
b.Transports larger or charged molecules
Facilitated diffusion (Channel Protein)
Diffusion (Lipid
Bilayer)
Passive Transport: 2. Facilitated Diffusion
Carrier Protein
A B
• http://bio.winona.edu/berg/Free.htm
Types of Transport• Active Transport Active Transport
– moves from an area of low concentration to an area of high concentration.
– Moves up or against the concentration gradient.
– Glucose moving from blood stream into liver for storage.
Types of Transport
• Bulk TransportBulk Transport– Moving large particles across the cell
membrane.
– Endocytosis - movement – into the cell
– Exocytosis - movement out of the cell
Bulk Transport
• Endocytosis - 2 types
– Pinocytosis- bulk transport of liquids into the cell.
– Phagocytosis- “cell eating”- bulk transport of solids into the cell.