unit 3 lecture 3. diffusion diffusion movement of substances from an area of high concentration to...
DESCRIPTION
Diffusion – cont’d Concentration Gradient – difference in concentration of a substance over a certain area “with/down” the gradient = particles move from area of high conc. to low conc. typical diffusion; natural movement “against” the gradient = particles move from area of low conc. to high conc. non-natural movement; requires ETRANSCRIPT
Unit 3 – Lecture 3
DiffusionDiffusion – movement of substances from an
area of high concentration to an area of low concentration
works to balance the concentration gradients of substances
ex: perfume in a room, dye in a glass of water…
Diffusion – cont’dConcentration Gradient – difference in
concentration of a substance over a certain area
“with/down” the gradient = particles move from area of high conc. to low conc.typical diffusion; natural movement
“against” the gradient = particles move from area of low conc. to high conc.non-natural movement; requires E
Diffusion – cont’dDynamic Equilibrium – a balance of the
distribution of particles in an area acknowledging the constant movement of the particles
dynamic – opposite of sta(tic/sis)indicates constant change
Diffusion – cont’dDiffusion often occurs through one of two types
of membranes:permeable membrane
allows all molecules [solute, solvent, or other particle] to pass through
semi/selectively permeable membraneallows only certain substances to pass
throughwhich type of membrane do cells have?
Diffusion DrawingsProblem: In a membrane selectively
permeable to X molecules, there are:4 particles of X [3 left, 1 right]12 particles of O [2 left, 10 right]
Based on the given information, identify & understand the type of membrane draw before & after beaker with membrane
Problem: In a membrane selectively permeable to X molecules, there are: 4 particles of X [3 left, 1 right]; 12 particles of O [2 left, 10 right]
Based on the given information, identify & understand the type of membrane draw before & after beakers with membrane
Problem: In a membrane selectively permeable to X molecules, there are: 4 particles of X [3 left, 1 right]; 12 particles of O [2 left, 10 right]
before beaker:under beaker, record # of particles per sidedraw # particles in beaker
X = 3 X= 1O = 2 O = 10
Problem: In a membrane selectively permeable to X molecules, there are: 4 particles of X [3 left, 1 right]; 12 particles of O [2 left, 10 right]
before beaker:determine directions of particle movement
X = 3 X= 1O = 2 O = 10
Problem: In a membrane selectively permeable to X molecules, there are: 4 particles of X [3 left, 1 right]; 12 particles of O [2 left, 10 right]
before beaker:above, draw arrows specifying how particles
will move
X = 3 X= 1O = 2 O = 10
Problem: In a membrane selectively permeable to X molecules, there are: 4 particles of X [3 left, 1 right]; 12 particles of O [2 left, 10 right]
before beaker:large arrow = larger movement [specify type of
particle]
X = 3 X= 1O = 2 O = 10
X
Problem: In a membrane selectively permeable to X molecules, there are: 4 particles of X [3 left, 1 right]; 12 particles of O [2 left, 10 right]
before beaker:small arrow = smaller movement [specify type
of particle]
X = 3 X= 1O = 2 O = 10
X
Problem: In a membrane selectively permeable to X molecules, there are: 4 particles of X [3 left, 1 right]; 12 particles of O [2 left, 10 right]
after beaker:under beaker, record new # of particles per
side
X = 3 X= 1O = 2 O = 10
X
X = 2 X= 2O = 2 O = 10
Problem: In a membrane selectively permeable to X molecules, there are: 4 particles of X [3 left, 1 right]; 12 particles of O [2 left, 10 right]
after beaker:draw # of particles in beakers
X = 3 X= 1O = 2 O = 10
X
X = 2 X= 2O = 2 O = 10
Problem: In a membrane selectively permeable to X molecules, there are: 4 particles of X [3 left, 1 right]; 12 particles of O [2 left, 10 right]
after beaker:draw appropriate arrows [specify type of
particle]
X = 3 X= 1O = 2 O = 10
X
X = 2 X= 2O = 2 O = 10
X
OsmosisOsmosis – diffusion of water across a
selectively permeable membranemembrane allows ONLY water to go through
solute particles NEVER movewater must be used to reach dynamic
equilibriummore water moves to where there is more
solute
Osmosis – cont’dEx: which has the higher concentration of solute?
how can you make the concentrations equal?
5 scoops of lemonade in a pitcher filled with 8 ounces of water5 scoops of lemonade in a pitcher filled with 1 gallon of water
Osmosis DrawingsProblem: With a membrane selectively
permeable to water, there are:4 particles of X [3 left, 1 right]
Based on the given information, identify & understand the type of membrane draw before & after tubes with membrane
Problem: With a membrane selectively permeable to water, there are: 4 particles of X [3 left, 1 right]
Based on the given information, identify & understand the type of membrane draw before & after tubes with membrane
Problem: With a membrane selectively permeable to water, there are: 4 particles of X [3 left, 1 right]
before tube:under tube, record # of particles per sidedraw # particles in tube
X = 3 X= 1
Problem: With a membrane selectively permeable to water, there are: 4 particles of X [3 left, 1 right]
before tube:determine directions of particle movement
X = 3 X= 1
Problem: With a membrane selectively permeable to water, there are: 4 particles of X [3 left, 1 right]
before tube:above, draw arrows specifying how particles
will move
X = 3 X= 1
Problem: With a membrane selectively permeable to water, there are: 4 particles of X [3 left, 1 right]
before tube:large arrow = larger movement [specify type of
particle]
X = 3 X= 1
H2O
Problem: With a membrane selectively permeable to water, there are: 4 particles of X [3 left, 1 right]
before tube:small arrow = smaller movement [specify type
of particle]
X = 3 X= 1
H2O
Problem: With a membrane selectively permeable to water, there are: 4 particles of X [3 left, 1 right]
after tube:under tube, record # of particles per side
X = 3 X= 1
H2O
X = 3 X= 1
Problem: With a membrane selectively permeable to water, there are: 4 particles of X [3 left, 1 right]
after tube:draw # of particles in beakers AND water level
X = 3 X= 1
H2O
X = 3 X= 1
Problem: With a membrane selectively permeable to water, there are: 4 particles of X [3 left, 1 right]
after tube:draw appropriate arrows [specify type of
particle]
X = 3 X= 1
H2O
X = 3 X= 1
H2O
What happens to cells?Hypertonic Solution – solution outside of the
cell has a higher concentration of solute than inside of the cell.
“hyper” = more than normalwater moves out of cellcell shrinks
Why is this bad for the cell?
What happens to cells? – cont’dIsotonic Solution – solution outside of the cell
has the same concentration as the solution inside of the cell.
concentrations are equalcell remains the same size
What happens to cells? – cont’dHypotonic Solution – solution outside of the cell
has a lower concentration of solute than inside of the cell.
“hypo” = less than normalwater moves into the cellcell swells [possibly bursts]