Transcript Cell Transport

Cell Transport
Getting Into and Out of Cells
Types of Cell Transport
 Passive Transport
- no cellular energy required to occur
- goes with the concentration gradient
- diffusion
- facilitated diffusion
- osmosis
 Active Transport
- requires cellular energy to occur
- goes against the concentration gradient
- Endocytosis/Exocytosis
- Sodium Potassium Pump
Concentration Gradient
 The concentration gradient is the distribution of particles
across space from high to low concentration
Passive Transport
 Energy for passive transport comes from the molecules
themselves
 In passive transport, molecules move with the
concentration gradient
- move from high concentration to low concentration
Diffusion
 Primary means of cell transport
- molecules move from high to low concentration
- movement continues with the gradient until
the molecules are evenly distributed
- equilibrium is achieved
Facilitated Diffusion
 Particles move with the concentration gradient
across a transport protein in the membrane
- ions, sugar and amino acids all move into and
out of cells by facilitated diffusion
Osmosis
 The diffusion of water across a selectively permeable
membrane
- water moves from where there is more water to
where there is less water
- water moves toward higher conc. of dissolved
material - solute
Three osmotic environments
 Hypotonic environment
 Little(below) solute/lots of water
What happens when you place cells in an environment that is
hypotonic to it? Hmm
Animal Cell
Plant Cell
Hypotonic Environment
Animal Cell
Plant Cell
Before
Water Moves In
After
 burst
turgid
2nd type of Environment
Hypertonic
Lots of solute/little water
What happens when you place a cell in an environment that is
hypertonic to it? hmm
Hypertonic environment
Animal Cell
Plant Cell
Before
Water Moves
Out
shrinks
plasmolyze
3rd Environment
 Isotonic Environment
 Equal amounts of solute and water
 What happens to a cell in an isotonic environment? hmm
Isotonic Environment
Animal
Before
Plant
Water Moves
In and Out
at an equal
rate
No Change
After
No Change