Q: What causes a voltage to exist across the membrane in cells?


Read this paragraph and choose the correct option from the provided answers:

The active transport of ions across the cell membrane causes an electrical gradient to build up across this membrane. The number of positively charged ions outside the cell is usually greater than the number of positively charged ions in the cytosol. This results in a relatively negative charge on the inside of the membrane, and a positive charge on the outside. This difference in charges causes a voltage to exist across the membrane. Voltage is electrical potential energy that is caused by a separation of opposite charges, in this case across the membrane. The voltage across a membrane is the membrane potential . Membrane potential is very important for the conduction of electrical impulses along nerve cells. The membrane potential of a cell at rest is known as its resting potential , and is discussed below. A non-excited nerve cell is an example of a cell at rest.

 Choices:

- insulators

- increase in energy

- same charge

- difference in charges


A:
difference in charges