Ion transporter

As an ion pump transmembrane transport proteins are referred to in the biochemistry and physiology that regulate the transport of certain ions across a biological membrane. The lipid bilayer of biological membranes is charged molecules, including ion- impermeable. The transport ion pump is one of the specific mechanisms to ensure a regulated exchange of ions through the membrane and maintain the concentration differences of ions between the two sides of the membrane. In contrast to ion channels thereby an energetically favorable is coupled with an energetically unfavorable reaction principle.

Types of ion pumps

There are two basic types of ion pumps:

• Firstly, the pumping of the active transport which, under energy consumption (hydrolysis of ATP to ADP or with light energy ) certain ions are transported against their concentration gradients ( their material gradients ). An example of this is the sodium-potassium ion pump ( ATPase), which produces not only the resting potential in the nerve cells, but in almost all cells of the human body maintains the osmotic balance between the extracellular and intracellular space.

• As a second type of ion pumps are called transmembrane proteins that allow ions along a concentration gradient, and thereby convert ADP to ATP and thus exploit the energy of the gradient. In this way is synthesized by utilizing a proton ATP from ADP, for example, in the ATP synthase in the mitochondria.

Examples

• Sodium-potassium ion pump
• Calcium pump of the sarcoplasmic and endoplasmic reticulum ( SERCA )
• Proton pump: ATP synthase
• Channelrhodopsins
• Bacteriorhodopsin