4.1 Cell membrane structure + functions Flashcards
What is the majority of the cell membrane made from?
Phospholipids
what are phospholipids?
type of lipid with a hydrophilic phosphate head and hydrophobic fatty acid tails
how are phospholipids arranged in the cell membrane?
as a bilayer, phosphate heads facing out and fatty acids facing in
what molecules are there in the cell membrane?
channel protein, carrier protein and proteins that only go halfway through membrane and cholesterol
what do channel proteins do?
(specific, passive process)
they allow ions to go through the cell membrane
e.g K+, Ca2+ and Na+
what do carrier proteins do?
(specific, active process)
they allow large molecules to go through
e.g. glucose
what passes through channel, carrier and phospholipids?
channel - ions
carrier - large molecules
phospholipids - lipid soluble, small molecules, non charged
what are glycoproteins?
a protein that is linked to a carbohydrate chain
what are glycolipids?
a phospholipid that is linked to a carbohydrate chain
what is the function of glycoproteins and glycolipids?
cell recognition (antigens, receptors, etc)
formation of tissues
what is the function of cholesterol in the cell membrane?
controls fluidity and stability
why is the fluid mosaic model called that?
fluid - molecules can move about within the bilayer
mosaic - membrane is made from different molecules
e.g. phospholipids, protein, cholesterol
