Download Membrane Structure

THE CELL MEMBRANE
AKA. THESE NOTES ARE A BIT
LONGER BUT YOU HAVE A QUIZ NEXT
WEEK AND I WANT YOU TO BE
READY.
Przeworski
Functions of The Cell Membrane
- Regulates what enters
and exits the cell
(homeostasis)
- Gives a cell shape
and support
HOMEOSTASIS
• The process of maintaining a stable
internal environment
• Example: Air Conditioning, Sweating
The Phospholipid Bilayer
- Cell membranes are made of phospholipids
Fatty acid
Fatty acid
The Phospholipid Bilayer
- Phospholipids have a hydrophilic head and a
hydrophobic tail
Water Fearing
Water Loving
The Phospholipid Bilayer
- The membrane is selectively permeable: it allows only
certain molecules to pass through
- Some very small molecules can pass directly between
the phospholipids
- CO2
- O2
- H2O
The Phospholipid Bilayer
- Large or charged
molecules must pass
through transport
proteins
- 3 types:
- Channel
- Carrier
- Pump
Pump
Channel
Carrier
The Fluid Mosaic Model
- The lipid bilayer is described as a
fluid mosaic:
- Fluid – components of the two
layers can move side to side
freely
- Mosaic – pattern created by
scattered proteins embedded in
lipid bilayer (chocolate chip
cookie)
Other Components
- Glycoproteins (keys): help cells recognize other cells
with attached carbohydrate chains
Other Components
- Cholesterol: found only in animal cell
membranes, helps maintain fluidity
VIDEO
• https://www.youtube.com/watch?v=6fhbbFd4icY
Solutes, Solvents, and
Solutions
Solute: Substance that
dissolves in the solvent
Solvent: Substance in
which the solute dissolves
Solution: Mixture of 2 or
more substances
More Simply…
Solute + Solvent = Solution
Solutes are usually solids/powders
Solvents are usually liquids
A few more examples…
• Gatorade (Powder, water)
• Coffee (Sugar, coffee)
• Saltwater (Salt, water)
15
TYPES OF SOLUTIONS
• Isotonic
A solution with a solute concentration
that is equal to the solute concentration
inside a cell.
TYPES OF SOLUTIONS
• Hypertonic
A solution with a solute concentration
that is higher than the solute concentration
inside a cell
TYPES OF SOLUTIONS
• Hypotonic
A solution with a solute concentration
that is lower than the solute concentration
inside a cell
POSTER PROJECT (DUE TODAY!)
• 1= Hypertonic, Hypotonic, Isotonic
When
you
finish,
get
a
• 2= Solute, Solvent, Solution
grade check sheet and
turn both in!
• Make a poster that shows the difference between
the three terms. Include a picture, explanation,
and color!
• You can do a meme, comic, or poster. Be creative!