Bio chapter 5 Flashcards
Plasma membrane/cell membrane separates what
Separates life from non living
The cells interior from external environment
Membrane function is to
Keep damaging material out of cell
Allow entry of materials
Facilitate chemical reactions
Phospholipid bilayers
When amphipathic lipids are in water what happens
Hydrophilic heads interact with water
Hydrophobic tails interact with each other away from water
If phospholipids are placed in water, they form into
Micelles(short) / lipid bilayers(long)
How does lipid structure affect membrane permeability
Bond saturation
Hydrocarbon chain length
Number of cholesterol molecules
Lipid bilayer with short and unsaturated hydrocarbon tails have a higher permeability or lower permeability
Higher permeability
J. Danielli & H. Davison (mid 1930s)
Propose a sandwich model
J.D Robertson (Late 1930s)
Proposed a unit model
J. Singer & G. Nicolson (1970s)
Protein phospholipids maximize content
E. Gorter & F. Grendel (mid 1920s)
Are there enough phospholipid to make bilayer
What is the process of visual membrane proteins
- Fracture cell
- Separate the parts
- Microscopy
- Interpretation
S. Singer & G. Nicolson (early 1970s)
Proposed what
What three components
Proposed fluid-mosaic model
The three components: phospholipid bilayer, protein molecules, and cholesterol
Where are peripheral protein found
What are integral protein
Found on inner membrane surface
Are partially embedded in the membrane
Proteins can insert into a membrane and can be
Proteins can also
Amphipathic because the side chains can be polar, charged, or non polar
Protein can fold into shapes
Fluid-Mosaic is
Cell membrane structure
