Cell membrane structure

2. •Gatekeeper
•Regulates what comes in and out
of the cell
•Main components: proteins and
phospholipids
•The cell membrane is selectively
permeable
•Allows some things through without energy,
but not everything

3. 1.All cells have a cell
membrane
2.Functions:
a.Controls what enters and
exits the cell to maintain
an internal balance
called homeostasis
b.Provides protection and
support for the cell TEM picture of a
real cell
membrane.

4. •Found only in plant cells and bacteria
cells
•Main function is support

5. •phosopholipids
•made of two sides: head and tail
•the head is hydrophillic (able to
interact with water)
•the tail is hydrophobic (not able to
interact with water)

6. 1.Structure of cell membrane
Lipid Bilayer -2 layers of
phospholipids
a.Phosphate head is polar
(water loving)
b.Fatty acid tails non-polar
(water fearing)
c.Proteins embedded in
membrane
Phospholipid
Lipid Bilayer

7. •carrier proteins
•allow larger or difficult molecules to get
through the membrane
•sometimes they require energy to
open/close like a door
•other times they simply act as a tunnel

8. Proteins
Membrane movement animation
Polar heads
love water &
dissolve.
Non-polar
tails hide
from water.
Carbohydrate cell
markers
Fluid Mosaic
Model of the cell
membrane

9. 4. Cell membranes have pores (holes) in it
a.Selectively permeable: Allows some
molecules in and keeps other molecules out
b.The structure helps it be selective!
Pores

10. Outside of cell
Inside of cell
(cytoplasm)
Lipid
Bilayer
Proteins
Transport
Protein
Phospholipids
Carbohydrate
chains
Structure of the Cell Membrane
Go to
Section:
Animations
of membrane
structure