Warm-Up
Answer the following questions in complete sentences.
Who discovered the first living cells?
The person who first discovered living cells was…
What are three things prokaryotic and eukaryotic
cells have in common?
Three things prokaryotic cells and eukaryotic cells have in
common are…
Who discovered the first living cells?
1.
2.
3.
4.
Robert Hooke
Antoine Von Leeuwenhoek
Dr. Gero
James Watson
What are three things prokaryotic and eukaryotic
cells have in common?
1.
2.
3.
4.
DNA, nucleus, and cell wall
Cell membrane, ribosomes, and DNA
Mitochondria, chloroplasts, and vacuoles
Ribosomes, plasma membrane, and membrane-bound organelles
Passive Transport
UNIT
4
Passive Transport
• The cell membrane takes
nutrients in and sends waste out
UNIT
Nutrients
Waste
4
Passive Transport
• The cell membrane takes
nutrients in and sends waste out
• Diffusion = movement WITH the
concentration gradient
UNIT
4
UNIT
Passive Transport
4
• The cell membrane takes
nutrients in and sends waste out
• Diffusion = movement WITH the
concentration gradient
High concentration
• Concentration gradient =
direction from high concentration
to low concentration across a
membrane
Low concentration
UNIT
Passive Transport
• The membrane is made out of
phospholipids with hydrophilic
heads and hydrophobic tails.
4
Hydrophilic
Head
Hydrophobic
Tails
Passive Transport
• The membrane is made out of
phospholipids with hydrophilic
heads and hydrophobic tails.
 Water and large molecules
cannot pass through the
membrane.
UNIT
4
Passive Transport
• The membrane is made out of
phospholipids with hydrophilic
heads and hydrophobic tails.
 Water and large molecules
cannot pass through the
membrane.
UNIT
4
Passive Transport
• The membrane is made out of
phospholipids with hydrophilic
heads and hydrophobic tails.
 Water and large molecules
cannot pass through the
membrane.
 Instead, water and large
molecules move through
channels in a process called
facilitated diffusion.
UNIT
4
Turn-and-Talk
With a partner, answer these two
questions:
• Why is water not able to pass through the
middle of the phospholipid bilayer?
Water is not able to pass through the middle
of the phospholipid bilayer because…
• How does facilitated diffusion help water and
large molecules travel across the membrane?
Facilitated diffusion helps water and large
molecules travel across the membrane by…
UNIT
4
Gummy Bear Lab
We will investigate how water moves
across the membranes in gummy bears.
With a partner:
• Get a cup and put your initials on it
• Get a gummy bear and put it in
• Come to me to get a mystery solution
UNIT
4
Closure
Answer the following question in a
complete sentence:
Why does water have to use facilitated diffusion to
cross the cell membrane?
Suggested sentence stem:
Water has to use facilitated diffusion to cross
the cell membrane because…
Name/Nombre
Date/Fecha
Period ____