Cell membranes Flashcards
cell membrane
the selectively permeable membrane which surrounds the cytoplasm of a cell, acting as a barrier between the cell contents and their surroundings
organelles
sub-cellular bodies found in the cytoplasm of cells
enzymes
proteins that act as biological catalysts for a specific reaction or group of reactions
vesicles
membrane ‘bags’[ that hold secretions made in cells
phospholipids
chemicals in which glycerol bonds with two fatty acids and an inorganic phosphate group
polar lipids
lipids with one end attached to a polar group (e.g a phosphate group) so that one end of the molecule is hydrophilic and one end is hydrophobic
hydrophilic
a substance with an affinity for water that will readily dissolve in or mix with water
hydrophobic
a substance that tends to repel water and that will not mix with or dissolve in water
micelles
a spherical aggregate of molecules in water with hydrophobic areas in the middle and hydrophilic areas outside
bilayer
a double layer of closely packed atoms or molecules
unit membrane
a lipoprotein membrane which is composed of two protein layers enclosing a less dense lipid
fluid mosaic model
the current model of the structure of the cell membrane including floating proteins forming pores, channels and carrier systems in a lipid bilayer
gated channels
protein channels through the lipid bilayer of a membrane that are opened or closed, depending on conditions in the cell
glycoproteins
conjugate proteins with a carbohydrate prosthetic group
