membranes Flashcards
(9 cards)
what are the features of a biological membrane
- barrier
- selective permeability
- contains lipids and protiens
- internal and external membranes
what is meant by selectively permeable
allows the cell to control which molecules can pass through the membrane moving into or out of the cell
what is plasma membrane
structure in which proteins float in sea of lipids
what can proteins be
pumps, channels, receptors, energy transducers and
enzymes
what is the structure of a lipid
hydrophobic and hydrophillic parts, glycerol is main backbone and fatty acid chain (non polar) or phospho group (polar)
what is a fatty acid
Long hydrocarbon chains of various
lengths and degrees of unsaturation
terminated by a carboxylic acid group.
what part of membrane is highly impermeable
lipid bilayer to ions and most polar molecules
how are peripheral and intergral protiens held in lipid bilayer
peripheral - h bonds and electrostatic forces
integral - hydrocarbon chains
