Question

Gorter and Grendel's classic conclusion that the plasma membrane of the human erythrocyte consists of a lipid bilayer was based on the following observations:(i) the lipids that they extracted with acetone from 4.74×109 erythrocytes formed a monolayer 0.89 m2 in area when spread out on a water surface;(ii) the surface area of one erythrocyte was about 100 μm2, according to their measurements.Show from these data how they came to the conclusion that the erythrocyte membrane is a bilayer.1) According to the given data, the number of erythrocytes should be 0.89×1012⋅100×10−4=8.9×109. This is almost twice the number of erythrocytes as Gorter and Grendel estimated it, leading to the conclusion that the surface of each cell was covered with three layers of lipid.2) According to the given data, the surface area of all erythrocytes is 4.74×109/100×108m2=0.47m2. This is almost a half of the surface area formed by a monolayer as Gorter and Grendel estimated it, leading to the conclusion that the surface of each cell was covered with two layers of lipid.3) According to the given data, each cell has a monolayer area of 0.89×1012/4.74×109=188μm2. This is almost twice the surface area of an erythrocyte as Gorter and Grendel estimated it, leading to the conclusion that the surface of each cell was covered with two layers of lipid.

Answer 1

The correct answer is: 2) According to the given data, the surface area of all erythrocytes is (4.74x10^9)/(100x10^8)m^2. This is almost half of the surface area formed by a monolayer as Gorter and Grendel estimated it, leading to the conclusion that the surface of each cell was covered with two layers of lipids.

Step-by-step explanation:

Each erythrocyte has a surface of 100 μm^2, which is equal to 100x10^-8 m^2. And to calculate the total area of erythrocyte counted, you should multiply the number of cells with the surface of one cell. This is (4.74x10^9)*(100x10^-8), which is equal to (4.74x10^9)/(100x10^8)=0.47m^2. This is approximately half of the surface area formed by the monolayer that was estimated. This is evidence that allows to conclude that the erythrocyte membrane is a bilayer