Cell membrane Flashcards
What are the purposes of the cell membrane?
Enclose a reaction compartment.
Maintain concentration gradients.
Quality control-determine what enters and leaves the cell.
Displays an interaction surface.
Acts as a barrier in aqueous environments.
What is phase seperation?
The separation of fluid phases that contain different concentrations of common components.
Polar vs apolar molecules.
Charged/polar molecules are highly soluble, as they’re attracted to waters dipole nature.
Apolar molecules are highly insoluble due to no attraction with waters dipole nature.
What’s an organic solvent?
Organic solvents are carbon-based substances capable of dissolving or dispersing one or more other substances.
What does amphiphilic mean?
Molecules containing polar and non polar groups, i.e. phospholipid.
Why are hexane and water insoluble in each other?
Hexane cannot form hydrogen bonds with water. … Water molecules and hexane molecules cannot mix readily, and thus hexane is insoluble in water.
How do amphiphilic molecules behave in aqueous solutions?
-Micelle formation:
Hydrophilic heads face aqueous environment, hydrophobic tails face inwards.
Micelle formation is essential for the absorption of fat-soluble vitamins and complicated lipids within the human body
What is lateral diffusion?
Diffusion/movement of lipids in a leaflet.
What is transverse diffusion?
Movement of phospholipids between leaflets, requires more time and energy then lateral.
What transport proteins are involved in transverse diffusion?
Flippases and Floppases.
What does membrane phase transition temp mean?
The temp which determines wether the phospholipid bilayer is gel like or solid.
What did Singer and Nicolson propose in 1972?
The fluid mosaic model.
