can lipid molecules flip flop across a membrane
Maintenance of membrane asymmetry in the resting state cannot be mediated by passive lipid flip-flop alone, since spontaneous translocation of phospholipids across the bilayer has been postulated to be extremely slow (10 â15 s â1), on average a single lipid flip-flop event every 24 h [8] and [9] .ransbilayer lipid motion has been dubbed flip-flop and it is unfortunate that this rather childish term has stayed in the scientific literature, together with the flippase and floppase terms that designate lipid translocating enzymes.