Download Cell Membrane

Cell Membrane
Plasma Membrane
Cell Membrane
• 2 layers (bilayer) of phospholipids
• Similar to a mayonnaise sandwich
– 2 pieces of bread with may stuck together
• Each individual phosphoplipid has a
– head that is hydrophilic
– tail that is hydrophobic
The phospholipid
STOP!! BIG WORDS!!!!
• Hydrophobic: Hydro = Water ; Phobic = afraid
– The tail of the phospholipid is hydrophobic
• Hydrophilic: Hydro = Water ; Philic = loving
– The head of the phospholipid is hydrophilic
• Millions of these molecules line up together to form
a cell membrane!
What is the cell membrane for?
Head
• Controls material
going into the cell
• Controls material
going out of the cell
• Holds the cell together
• Able to “talk” with
other cells and
molecules
Phospholipid
Tail
Cell Membrane
Cell Membrane
• Membrane looks big?
Picture this…….
• It would take 10,000
membranes to equal the
thickness of one sheet
of paper!!!
Cell Membrane
Cell Membrane Proteins
• Proteins are stuck
throughout the cell
membrane
• They act as tunnels
letting large molecules
into and out of the cell
Receptor Molecules
• Molecules that that help the cell “talk” with
other cells or molecules
• Must fit together like a puzzle piece
Keep in mind…...
• Not all substances can pass through the cell
membrane!!! Only certain substances when
needed…….this is called
SELECTIVE
PERMEABILITY….
• Know what this means……