UNIT 1
Cell
Membranes
Mrs. McGee
Do Now
 Can
drinking too much water kill you?
Explain…
Learning Goal

Students will understand why cells are
enclosed within a semipermeable membrane
and how the membrane regulates their
interaction within their surroundings. (NGSS HSLS1.A.)

VOCAB: cellular transport, lipid bilayer, fluid
mosaic model, polar/ non-polar, hydrophilic,
hydrophobic, diffusion, osmosis,
concentration, gradient, equilibrium
Monday’s Agenda
 Do
Now/ Collect HW
 Hypothesis
 Groups/ Set up Experiment
 Explore
 Notes
 Vocab Chart
Create Hypothesis
 If
I place an egg in vinegar
then____________________________________
__________________________.
 Write
this under your Do Now
Group Assignments
 3-5
Students per group
 Remember to use positive language
 Everyone completes their own worksheet
Start Experiment- 15mins
Your
group will be given 2 eggs
Record the weight and
circumference (widest part)
Write information in Day 1
Table
Caution: Because these are raw eggs, they may
carry salmonella, so you should use gloves when
handling the eggs.
NOTES
 Plasma
membrane= Cell Membrane
 Controls what enters and leaves a cell
 Provides protection and support
Plasma Membrane
Two
layers of lipids
Most contain protein molecules
embedded in the lipid bilayer
Carbohydrate chains are
attached to proteins
Cell Membrane=Semi-Permeable
 Permeable:
allowing liquids or gases to
pass through it
 Semi-permeable
means allowing certain
substances to pass through it but not
others.
Main Role
 Regulate
the interaction with the
surrounding environment and maintain
homeostasis
 Homeostasis:
The ability of the body or a
cell to seek and maintain a condition of
equilibrium or stability within its internal
environment when dealing with external
changes
Closing
 Complete
Quietly
 Answer question 1&2
 Finish for HW
Day 2: Tuesday’s Agenda
 Do
Now
 Check Experiment
 Notes
 Connections
Do Now
 What
is something similar to a cell
membrane?
 Example:
Day 2: Experiment- 10 minutes
 Observe
your eggs
 Carefully handle your now fragile egg!
 Dry each egg
 Measure the weight and circumference
 Record your results for Day 2 in the Table
If you finish early answer question #3
Experiment: Changing Liquids
 Empty
the vinegar from the container for
egg 1 and replace it with water to cover
the egg.
 Empty the vinegar from the container for
egg 2 and replace it with corn syrup to
cover the egg. As you pour the corn
syrup, notice that it is viscous (thick,
sticky).
If you finish early answer question #4
Notes
 REMINDER:
During notes you are silent
while the teacher is talking. If you have a
question or comment raise your hand and
wait silently to be called on.
 Diffusion:
the overall movement of a
substance (e.g., an atom, ion or
molecule) from a region of high
concentration to a region of low
concentration.
 Smaller
molecules can move freely
between the inside and outside of cell
membrane. Larger molecules cannot
diffuse through the cell membrane, and
require other mechanisms of transport to
move.
OSMOSIS

Osmosis: process by which water diffuses
through a selectively permeable membrane.
In this case, the cellular membrane.

Water moves from an area where there are
fewer molecules to an area where there are
more molecules

Low solutes High solutes
Day 3: Thursday’s Agenda
 Do
Now
 Check Experiment
 Answer Questions
DO NOW
Share what you see in this
piece of art. Think.Write.Share
Day 3- Experiment
 Answer
Questions #5-6
 Rinse the corn syrup off of egg 2
 Dry each egg
 Measure and record the weight and/or
circumference for day 3 in the table
Egg 2
 Place
egg in water
 Add 1 drop of
 food coloring
Clean Up
 Throw
away Egg 1
 Rinse out container
 Wipe off scales
Closing
 Answer
questions 7-8
Optional VIDEO
 https://www.youtube.com/watch?v=Pfu1
DE9PK2w
 Optional

Activity
Food Coloring Activity
Day 4: Friday’s Agenda
 Do
Now
 Reflections
 Understanding Osmosis WS
 Re-evaluate Big Question

Can water kill you? Why…
Check on Egg 2
 Remove
Egg 2
 Observe


What happened?
How does this happen?
 CLEAN
UP  Throw away Egg, Rinse out
container, Wipe off scales and lab area
Complete Osmosis WS
 Work
in Groups
HW- LAB REPORT
 Requirements
Typed!
 Complete Individually
 Use Notes & Worksheet
 DUE FRIDAY OCT. 2nd