Topic 3 - Membranes Flashcards
which membrane lipids are associated with the cytosolic side?
phosphoglycerides, sphingolipids, and sterols
which membrane lipids are associated with the extracellular side?
sterols and glycolipids
which membrane lipids have fatty chains? which have fatty tails?
fatty chains: sphingolipids, glycolipids
fatty acid tails: phosphoglycerides, sphingolipids, glycolipids
can any membrane lipids have negative charge?
phosphoglycerides and sphingolipids (phosphate group) also glycolipids
eukaryotes vs prokaryotes for lipid composition
eukaryotes have many more types of lipids
prokaryotes have one main type
variation in lipids comes from what?
different head groups, number of carbons in carbon chains, and different cis bonds
what is the impact of cis-double bonds
makes unsaturated chains
the kinks prevent stiffness to keep membrane fluid at low temperatures
what is desaturase
an enzyme that plants make that introduces double bonds during cold temperatures
why is asymmetry in lipid bilayer important?
converts extracellular signals to intracellular ones
what are the uses of beta-barrel proteins
receptor or channel for ion transport, porin, lipase
which lipid anchor membrane proteins are reversible?
thioester linkage
which lipid anchor membrane proteins are irreversible
amide linkage and thioether
where are sugars added to glycoproteins
in the ER
what type of membrane proteins are important for protein recognition and protection from mechanical and chemical damage?
glycoproteins! –> form extracellular carbohydrate layer
do tertiary structures have asymmetry?
yes. and they have disulfide bonds between themselves and other proteins on extracellular side, not cytosolic
