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The cell membranes have 60% of proteins and 40% of lipids. And we know that medium density of proteins is 1,2 g/cm3 and the medium density of lipids is 0.92 g/cm3.

  1. How can we calculate the medium density of the whole membrane ?
  2. If we centrifuge this membrane in a substance of 1.095 g/cm3 in density, could it be settled ?

Sorry for my bad english.

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I this by any chance a type of homework question? If so, please add the tag and show us your thoughts and how far you got. –  Chris Mar 22 at 19:49
This is my answer to the first question: medium density : (1.2 * 60) + ( 0.92 * 40 ) / 100 = 1.088 g/cm3 –  Younesse Bagachoul Mar 22 at 19:59
I just don't understand the second question. Please help –  Younesse Bagachoul Mar 22 at 20:07
If the density of the medium ("substance") is greater than the density of the membranes (which is what you have calculated) what do you think would happen? - the membranes are less dense than the medium. –  Alan Boyd Mar 22 at 23:15
@AlanBoyd That's the part I really don't understand : What would happen if the membranes are less dense than the medium. The teacher had not explained this :/ –  Younesse Bagachoul Mar 23 at 11:48

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