Question

g The membrane around a cell normally has layers of charge that create a potential difference between its outer and inner surfaces. This difference is about 82 mV . Part A When a singly ionized potassium ion moves through a channel in the membrane passing from the outside to the inside, what is the magnitude of the work done by the electric field of the membrane?

Answer 1

Answer:

1.31*10⁻²⁰ J

Explanation:

• As the potential is the work per unit charge, we can find the work done by the electric field created by the charge, just multiplying the potential difference times the charge acted by the field.
• A singly ionized potassium ion has a charge equal to a positive elementary charge, e.
• So, the work done by the field can be found as follows:

        $W = e*\Delta V$

• where e = 1.6*10⁻¹⁹ C and V= 82 mV
• Replacing by the values, we finally get:

        $W = e*\Delta V = 1.6e-19 C * 82e-3 V \\W = 1.31e-20 J$

• The magnitude of the work done by the electric field of the membrane is 1.31*10⁻²⁰ J