Cell Transport
Cell TransportOsmosis and Diffusion
Particles in constant motionRun into each other and randomly spread out
Particles move from an area of high concentration to an area of low concentrationDiffusion
DiffusionCan occur across membranes IF the particle can cross the membrane
Does not require energy Passive transport
TimeSemipermeableFacilitated DiffusionMolecules that cant pass directly through membrane may pass through a protein channel in membrane
Still no energy = passive transport
OsmosisSpecific type of facilitated diffusionDiffusion of water through a selectively permeable membrane
Is energy required?
Osmosis, contdWater moves from an area of high concentration to an area of low concentration.
When comparing two solutions:Hypotonic below strength; lower concentration of solute, higher concentration of waterHypertonic above strength; higher concentration of solute, lower concentration of waterIsotonic same strength; solutions have same concentration of solute and same concentration of water
Osmosis, contdWater moves from an area of high concentration to an area of low concentration.
1 % salt99% water0% salt100% waterIn which direction will water move? Into the cell our out of the cell?Water moves into cell(trying to reach equilibrium)
What will happen to the cell?Is the solution hypertonic, isotonic, or hypotonic?Hypotonic SolutionOsmosis, contdWater moves from an area of high concentration to an area of low concentration.
1 % salt99% water5% salt95% waterIn which direction will water move? Into the cell our out of the cell?Water moves out of the cell.
What will happen to the cell?Is the solution hypertonic, isotonic, or hypotonic?Hypertonic SolutionOsmosis, contdWater moves from an area of high concentration to an area of low concentration.
1 % salt99% water1% salt99% waterIn which direction will water move? Into the cell our out of the cell?No net movement of water!
What will happen to the cell?Is the solution hypertonic, isotonic, or hypotonic?Isotonic Solution
Active TransportAllows movement of particles against the concentration gradientIn other words, particles can move from low concentration to high concentration
Proteins in membrane pump the molecules in or outRequires energy Active transport
Passive vs. Active Transport
