Question

What are the similarities and differences, from an electrical point of view, between a cell membrane in the human body and two metal plates in a circuit, with an air gap between them?

Answer 1

In case of circuit , two metal plates with air gap in between them , when we apply voltage to them electric field is created. Positive charge collect on one plate and negative charge on other. Thus it stored energy and acts as a capacitor.

In case of human body , cell membrane is double layer of protein or lipids that surround the cell. It acts as capacitor such that it allows more current to flow if a voltage is changing rapidly. Hence it controls electrically charged ions across the cell membrane.

In case of metal plate we can physically controls the voltage and gap between the plates.

But in human body we can't change distance between layer of plasma membrane or voltage also.