Cell Transport
BLOCK Day: notes & Lab set up
Bellwork
1. What is concentration? (NOT the kind where
you’re thinking really hard…)
2. Why is the orange juice you mix with water
called “concentrate”?
3. Draw a picture showing the difference between
the molecules in a LOW concentration solution
vs a HIGH concentration solution
4. What is the difference between being passive
and being active?
Cell Membrane Notes (in notebook)
• Copy down only most important things from
each slide.
ON ODD PAGES
INFO
3 drawings/diagrams
3?
1 memory strategy
summary
2
On Slates:
name that
membrane
part (1-5)
phospholipid
5
3
1
4
MYON – Diffusion & Osmosis
•
•
•
•
•
•
Semi-permeable
Solute
Solvent
Solution
Simple Diffusion
Concentration
Gradient
• Osmosis
• Golden Rule of
Osmosis



Hypotonic
Isotonic
Hypertonic
Being Semi-permeable
Selective Permeability
Certain molecules can pass through
and others are prevented.
Which part of the cell is semipermeable?
Look around the room, can you
name some things that are
permeable and not permeable?
Why is permeability important?
 Small molecules, such as O2 & CO2, can enter
and leave the cell freely.
 Large molecules such as proteins and carbs
can’t.
 Several processes are involved in moving
materials across the membrane.
 THINK: Which is passive and which is ‘active’?
What do these key terms mean?
• SOLUTION
• Solute
• Solvent
Solution
• What are
examples of
each?
Solute
Solvent
Concentration
• Concentration: How close together molecules
are in a solution; the amount of solute in a
particular amount of solvent
• Which beaker has a higher concentration of
food coloring?
Passive Transport
• A concentration gradient is a
measurement of how the
concentration of something
changes from one place to
another.
Passive Transport
• No energy required
• Solutes are moved down the
concentration gradient:
–Osmosis
–Diffusion
–Facilitated diffusion
Passive Transport
• Osmosis- the
movement of water
across a semipermeable membrane
from an area of low
solute concentration to
an area of high solute
concentration
Hear Ye! Hear Ye! This is the Golden
Rule of Osmosis:
• Why? You ask…
– If the solute could spread out, it would. (
The Laws of Physics DEMAND it )
– But when a semi-permeable membrane
stops them, there is only one thing that
can move
– What is that?
The Solvent
• Which in the case of almost every single
biological situation is going to be our good
friend…
WATER
The WATER will move to
make the spaces between
the solute even out.
This might mean the cell
swells up.
shrinks or
The water doesn’t care
what the effect is on the
cell because in OSMOSIS…
BELLWORK:
Explain & diagram what is happening when you drop a
plant cell into distilled water, and into salt solution. Label
(solute and solvent) and water movement using an
arrow.
Passive Transport
• Simple Diffusionmovement of molecules
(a solute) from an area
of high concentration to
an area of low
concentration
Simple Diffusion- movement
of molecules (a solute) from an
area of high concentration to an
area of low concentration
But wait, what’s a solute?
+
Solute
(Kool-Aid powder)
=
Solvent
(water)
Solution
(Kool-Aid)
Solute: a substance that is dissolved in
something else (the solvent).
Small
dish of
water
Simple Diffusion
What will happen to
the “molecules” of
Kool-Aid?
They will
diffuse!
“Molecules”
of Kool-Aid
Slate Work
1. Draw where the solute (Kool-Aid
molecules) will be in 10 hours.
2. Write out the word for this process.
3. Think to yourself: did this happen all at
once? What was the process?
Simple Diffusion
Concentration Gradient:
difference in
concentration of a solute
across a region
How would you describe this concentration gradient?
Putting it all together so far…
Solutes diffuse along a concentration gradient from an area of
high concentration to an area of low concentration.
Which way
will the solute
diffuse?
What does that say about
diffusion and the use of energy?
For this to happen
is stirring
required?
Diffusion…it just
happens.
Too much stirring.
With your partner…
• Partner #1 – explain Osmosis and how is
works!
• Partner #2 – explain simple diffusion and how
it works!
Dialysis Tubing
• Is also IMPERMEABLE to sucrose…
• Which is good, because I made a bunch of
sucrose solutions of different
concentrations, and I can’t remember which
is which.
Dialysis Lab – Your Job
• Objective:
To determine which of the
unknown solutions is High, Medium and
Low concentration.
• Purpose: To observe the process of osmosis
first hand and to use this process to
understand how dialysis works.
Materials
• 3 Unknown colored solutions (High, Med and
Low Concentration)
• Water (150 mL)
• 3 beakers*
• 3 pieces of dialysis tubing*
• 3 pipettes
• Scissors
• Scale
• Paper towel
• Lab Title: Osmosis Lab (+ catchy title)
• Problem/Question: Does ______________ of
_________ in the bag affect the final ________ of
the bag in ___ after in soaks in water.
• Hypoth:
• if _________________ (color solution) has
(highest/lowest solute concentration) relative to
the
• Then _________________
• As measured by __________
Data table:
Mass of dialysis tubes in grams
COLOR
INITIAL
FINAL
Difference
High/Low/
Med
Red
Blue
Yellow
Diagram:
Draw all 3 set ups at the start of the experiment and 15 minutes later.
-Include particulate drawings showing H20, and sucrose molecules.
-Label the solute and the solvent.
-Use arrows to show the flow of water
• Materials:
• Procedures: 
• Data Table:
• Qual. Observations
• Graph: line/bar
• Conclusion