Question

What is the purpose of the Na+ and K+ pumps in animals?

Answer 1

The sodium-potassium pump performs several functions in cell physiology.

Explanation:

It is an enzyme that pumps sodium out of the cell while pumping potassium into the cells, against their concentration gradients.

The sodium-potassium pump helps maintain resting potential, effect transport, and regulate cell volume.

Resting potential:
The sodium-potassium pump helps to maintain the cell membrane potential. This mechanism moves three sodium ions out and two potassium ions in thus helping the cells to keep a low concentration of sodium ions and high concentration of potassium ions within the cells.

Transport:
The sodium-potassium pump provides a sodium gradient which is used by certain carrier processes. These processes occur in the gut as well as renal tubular system. Here this pump provides the driving force for several secondary active transporters which import glucose, amino acids and other nutrients into the cell by use of sodium gradient.

Controlling cell volume:
The pump helps to maintain the right concentration of ions. Failure of the sodium-potassium pump can cause a swelling of the cell resulting in its lysing.

Signal transducer:
The sodium-potassium pump can also relay extracellular ouabain binding signalling into the cell through regulation of protein phosphorylation. The following downstream events include activation of the mitogen-activated protein kinase signal cascades, mitochondrial reactive oxygen species production, as well as activation of phospho lipase C and inositol triphosphate receptor in different intracellular compartments.

Controlling neuron activity states:
This pump has shown to control and set the intrinsic activity mode of cerebellar Purkinje neurons, accessory olfactory bulb mitral cells and other neuron types. It has been suggested that the pump could also be a computation element in the cerebellum and the brain.

All mammals have four different sodium pump sub-types, or isoforms. Each has unique properties and tissue expression patterns.