Consider the following cell: it has a plasma membrane with surface area of 5000

Question

Consider the following cell: it has a plasma membrane with surface area of 5000 um2; there are 106 phospholipid molecules per um2 in each leaflet of the membrane; there are 3500 molecules of flippase enzyme associated with the plasma membrane; each flippase enzyme molecule can catalyze 100 flips per second (we'll ignore enzyme specificity for the moment) What is the maximum rate of inappropriate spontaneous phospholipid flips, in flips/sec for the whole plasma membrane, that can be reversed by the action of the flippases? Submit Answer Tries 0/3 What fraction of the total phospholipids in the plasma membrane can be flipped per hour? Submit Answer Tries 0/3 If each phospholipid in the plasma membrane flips spontaneously on average once every 105 seconds, are the 3500 molecules of flippase adequate to reverse the flips and keep the asymmetry of the lipid bilayer intact? Yes No Submit Answer Tries 0/1

Explanation / Answer

Note:-number of flippase taken 2000 instead of 3500 .

A.The flippases can catalyze: 2000 molecules x (100 flips /molecule) = 2 x 10 raise power 5 flips / sec

= 7.2 x 10raise power 8 flips / h

B.the cell has:(10 / :m) x (5000 :m/ leaflet) x 2 leaflets = 10phospholipid molecules total62210So, (7.2 x 10 / 10) = 8100.072 or 7.2% of the total P-lipids that can be flipped each.

C.yes.

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