Lecture 15 Flashcards
Describe the structure of the lipid bilayer.
Double membraned amphipathic structure with both lipids and proteins.
Describe the properties of the lipid bilayer.
Double membrane, proteins transfer nutrients in and waste products out, fluid dynamic structure, amphipathic.
What is the relevance of short hydrocarbon chains?
Lowers interection of the phospholipids and increases fluidity.
What is special about unsaturated membranes?
They increase fluidity.
What is also found in cell membranes?
Cholesterol and glycolipids
What is the role of cholesterol?
Decreases fluidity as it fills the spaces left by the kinks in their tails
Why is membrane fluidity important?
Allows membrane proteins to diffuse, fluid mosaic model
Why is the lipid bilayer asymmetrical?
Different phospholipids are spread differently throughout the membrane
What is always on the outside and inside of the membrane?
Glycolipids always on outside, except phosphatidylinositol which is always on the inside
What are flippases, floppases and scrambleases?
Flippases - outside in
Floppases - inside out
Scrambleases - both
Describe spectrin
the main protein in RBC that forms the cortex. attaches to ankyrin to provide cell structure
What ways can molecules and ions pass through the cell surface membrane?
Passive or active transport.
