Please answer the following ! Cell membranes (the walled enclosure around a cell

Question

Please answer the following !

Cell membranes (the walled enclosure around a cell) are typically about d = 7.6nm thick. They are partially permeable to allow charged material to pass in and out, as needed. Equal but opposite charge densities build up on the inside and outside faces of such a membrane, and these charges prevent additional charges from passing through the cell wall. We can model a cell membrane as a parallel-plate capacitor, with the membrane itself containing proteins embedded in an organic material to give the membrane a dielectric constant of about 42. (See the figure(Figure 1).) What is the capacitance per square centimeter of such a cell wall? Express your answer using two significant figures c = mu F/cm2 Submit MyAnswers Give Up Incorrect; Try Again; 3 attempts remaining In its normal resting state, a cell has a potential difference of 85mV across its membrane. What is the electric field inside this membrane? Express your answer using two significant figures. E = V/m Submit My Answers Give Up Incorrect; Try Again; 4 attempts remaining In this state, the electric field within the membrane is constant and the equation E = E0/k does not apply.

Explanation / Answer

a)

C=KeoA/d

C/A =Keo/d

C/A =42*8.85*10^-12/(7.6*10^-9)

C/A =0.0489 F/m^2

C/A =4.89*10^-6 F/cm^2

C/A =4.89 uF/cm^2

b)

E=V/d =(85*10^-3)/(7.5*10^-9)

E=1.133*10^7 V/m

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