Strand 4: Life Science
PO 3. Explain the importance of water to cells.
PO 4. Analyze mechanisms of transport of materials (e.g., water,
ions, macromolecules) into and out of cells:
 passive transport
 active transport
Announcements:
1) Everyone has started their month #1 observations for the HIC project
2) Come see me at lunch or after school to make up test grade
Red Onion Cells!
• https://www.youtube.com/
watch?v=nHWUAdkYq4Q
The phospholipid bilayer has pores (holes) to allow
SOME materials through that are small enough to fit
through the pores: Like WATER
Cells NEED water to survive – water passes in and
out of the cell membrane through the pores (holes)
to maintain equilibrium
How do our cells obtain water to survive?
Through the process
of OSMOSIS:
Movement of water
through a cell membrane
from an area of HIGH
concentration to LOW
concentration.
-This is Passive Transport:
Movement of water
without using energy
Water will always try to reach
equilibrium (equal amounts of water
inside and outside of the cell)
Solute Vs Solvent
Water will always try to reach equilibrium (equal
amounts of water inside and outside of the cell)
IF there is more water outside
the cell than inside, and a high
solute concentration inside the
cell, THEN the water will move
into the cell.
IF there is LESS water outside the
cell than inside and a high solute
concentration outside the cell,
THEN the water will move out of
the cell
Red Onion Cells One More Time!
• https://www.youtube.com/
watch?v=nHWUAdkYq4Q
Write in your Journal
I am looking for you to reference OSMOSIS and vocab terms.
• -How are isotonic sports drinks are meant to work?
• -How are they different from water
• -How are they different from a fizzy soda?
HW DUE Friday
Journal Checks
• Must have all notes
complete
Test corrections due Friday (NO
EXCEPTIONS) *optional – cannot use a late
pass*
– Finish cell webquest if you
didn’t finish in class
• Can earn back ½ pts you missed.
• Example:
#2: Lets say I chose the answer A:
Nucleus – as part of my test
corrections I would write:
#2: Correct answer: B:
Phospholipid Bilayer because the
above structure is composed of
hydrophobic tails and hydrophilic
tails which are essential in the
semipermeable cell membrane
How Osmosis Works
How Osmosis Works
• https://youtu.be/w3_8FSrq
c-I
Using an Egg to visualize Osmosis
• https://youtu.be/SSS3EtKAz
Yc
The best Osmosis Rap Song you will
ever hear….. True Story
Real osmotic disasters 
• https://youtu.be/HqKlLm2
MjkI