Download Chapter 3, Section 1 - Nogales High School

3.3 Cell Membrane
• In the top margin of pg 26:
Explain why animal cells cannot undergo
photosynthesis.
Hint: Look at the difference in organelles.
3.3 Cell Membrane
• Animal cells lack chloroplasts which is the
organelle needed to convert solar energy into
energy that the cell can use.
Animals cannot make their own
food…plants can because they have
chloroplasts!
3.3 Cell Membrane
Standard
1.a Students know cells are enclosed within a
semipermeable membranes that regulate their
interaction with their surroundings.
3.3 Cell Membrane
Sponge: Set up Cornell
Notes on pg. 29
Topic: 3.3 Cell
Membrane
Essential Question:
Explain how membrane
receptors transmit
messages across the
cell membrane
Cell Membrane
2.1 Atoms,3.3
Ions,
and Molecules
Explain how membrane receptors transmit
messages across the cell membrane
Key Concept: The cell
membrane is a barrier that
separates a cell from the
external environment
pg. 28
Phospholipid
3.3
Cell Membrane
Cell Membrane
“Selectively Permeable”
3.3 Cell Membrane
KEY CONCEPT The cell membrane is a barrier that
separates a cell from the external environment.
What can
we compare
this to in
our bodies?
3.3 Cell Membrane
•
The cell membrane has two major functions.
cell membrane
3.3 Cell Membrane
•
The cell membrane has two major functions.
1. forms a boundary between inside and outside of the
cell
cell membrane
inside cell
outside cell
3.3 Cell Membrane
•
The cell membrane has two major functions.
1. forms a boundary between inside and outside of the
cell
2. controls passage of materials
cell membrane
inside cell
outside cell
3.3 Cell Membrane
Cell membranes are composed of two phospholipid
layers.
3.3 Cell Membrane
•
A phospholipid is a molecule composed of three basic
parts:
head
A charged phosphate group
Glycerol
two fatty acid chains
tail
*Draw and label this phospholipid on the top
of pg 28
3.3 Cell Membrane
Head
• The head is polar
• interacts with water
• Hydrophilic
• Attracted to water
• The tail is non-polar
• repelled by water
• hydrophobic
• Attracted to other tails
Tail
3.3 Cell Membrane
*Phospholipids arrange themselves like a sandwich into
two layers.
Contain:
• Proteins
• Cholesterol
• Carbohydrates
cell membrane
carbohydrate
chain
cholesterol
protein
protein channel
protein
3.3 Cell Membrane
Pg. 28-middle: draw and label the cell membrane and its parts
carbohydrate
chain
cholesterol
protein
protein channel
protein
3.3 Cell Membrane
Fluid mosaic model:
• Flexible
• Phospholipids can move from side to side and slide past
one another
• Behaves like a fluid
3.3 Cell Membrane
•
The cell membrane is selectively permeable.
*Draw a
picture on the
bottom of pg.
28
Some molecules can cross the
membrane while others cannot.
3.3 Cell Membrane
•
The cell membrane is selectively permeable.
*Draw a
picture on the
bottom of pg.
28
Some molecules can cross the
membrane while others cannot.
3.3 Cell Membrane
Receptors are proteins that detect a signal molecule and
performs an action in response
– It binds with ligands on the outside of the cell
– Once they bind, the receptor changes shape and sends
a message to the inside of the cell
3.3 Cell Membrane
In Da Club Video Notes