diffusion catalyst: what is the function of the cell membrane? it was hot last night, so teyhones...
TRANSCRIPT
Diffusion
Catalyst: What is the function of the cell
membrane? It was hot last night, so Teyhones
turned on the air conditioning in his house. But his sister, Perrinika, accidentally left the front door open. What happened to the temperature in Teyhones’ house, and why? Be specific!
Write in complete sentences!
Don’t talk during the Catalyst!
Objectives
By the end of the period, all SWBAT…Predict the movement of molecules using diffusion
Definitions
Solution = a mixture of solute and solvent
Concentration = measurement of how much solute there is in the solvent High concentration: lots of solute, compared to
solvent Low concentration: little solute, compared to solvent
liquid
stufffinal product
Can you give me some examples?
Fill in the blanks: in _______________,
the _______________ is mixed into the
_______________.
SOLUTE
SOLVENT
SOLUTION
HIGH LOW
SolutesWhat do you think would happen if we opened up a path between these two boxes?
Concentration
75% Solute
5% Solute
Diffusion
Key Point #1: Diffusion is the net movement of molecules from an area of high concentration to an area of low concentration Molecules are always moving They bump into each other This knocks molecules from the area
of high concentration into the area of low concentration
Diffusion
75% Solute
25% Solute
65% Solute
35% Solute
50% Solute
50% Solute
Diffusion
Key Point #2: Diffusion continues until there is equilibrium Equilibrium = The point at which two connected solutions have equal concentrations
Diffusion
Diffusion moves toward equilibrium75% Solute
25% Solute
65% Solute
35% Solute
50% Solute
50% Solute
Demonstration
In notes answer these two questions I have a bottle of ink and a beaker of tap
water. Which has the higher concentration of ink? Predict what will happen if I put a couple of
drops of ink in the beaker of the water.
We will check in on this later on today…
Solutes move even when concentration is equal
“Net movement” of molecules
50% Solute
50% Solute
Demo!
LYSOL
Molecules move from HIGH concentration to LOW concentration
All this is great, but…
But what happens when you can’t just move from one area to another Like there might be something that controls what goes in and out…
Like a cell membrane…
Cell Membranes
Key Point #3: Cell membranes are selectively permeable Selectively permeable = only let
certain things pass through
Selectively Permeable Cell Membrane Cell membranes control what enters
and what leaves the cell Small things diffuse in, because they
can fit between the gaps in the cell membrane
Big things are kept out, because they cannot
-+
+-
The diagram below shows a cells, surrounded by a semi-permeable membrane, in the bloodstream.
How will the solute move, according to diffusion?
Example
10% Sugar Solution
80% Sugar Solution
Guided Practice
Provide your own example of a solution. Then, state what the solute and solvent in it are.
DO NOT USE HOT CHOCOLATE, OR ANY OTHER EXAMPLE WE HAVE DISCUSSED IN CLASS TODAY.
Guided Practice
The diagram below shows two cells, separated by a semi-permeable membrane.
How will the solute move, according to diffusion?
The diagram below shows two cells, separated by a semi-permeable membrane.
How will the solute move, according to diffusion?
Guided Practice
72% Sugar Solution
34% Sugar Solution
The diagram below shows two cells, separated by a semi-permeable membrane.
How will the solute move, according to diffusion?
Guided Practice
55% solute
85% solute
The diagram below shows two cells, separated by a semi-permeable membrane.
Draw what this situation will look like after diffusion has FINISHED.
Guided Practice
38% solute
41% solute
Guided Practice
“Diffusion causes solutions to move toward equilibrium.”
Describe what this means in your own words, and in complete sentences.
Exit Question
The diagram below shows two cells, separated by a semi-permeable membrane.
How will the solute move, according to diffusion?
When will net movement of the solute stop? Use the vocabulary we learned today!
Write in complete sentences!
Don’t talk during the Exit Question!