Search results
Results From The WOW.Com Content Network
Sodium channels are highly selective for the transport of ions across cell membranes. The high selectivity with respect to the sodium ion is achieved in many different ways. All involve encapsulation of the sodium ion in a cavity of specific size within a larger molecule. [3]
In many ion channels, passage through the pore is governed by a "gate", which may be opened or closed in response to chemical or electrical signals, temperature, or mechanical force. [citation needed] Ion channels are integral membrane proteins, typically formed as assemblies of several
Voltage-gated sodium channels (VGSCs), also known as voltage-dependent sodium channels (VDSCs), are a group of voltage-gated ion channels found in the membrane of excitable cells (e.g., muscle, glial cells, neurons, etc.) with a permeability to the sodium ion Na +. They are the main channels involved in action potential of excitable cells.
When ion channels are in a 'closed' (non-conducting) state, they are impermeable to ions and do not conduct electrical current. When ion channels are in their open state, they conduct electrical current by allowing specific types of ions to pass through them, and thus, across the plasma membrane of the cell. Gating is the process by which an ...
Ion channels are a type of transmembrane channel responsible for the passive transport of positively charged ions (sodium, potassium, calcium, hydrogen and magnesium) and negatively charged ions (chloride) and, can be either gated or ligand-gated channels. One of the best studied ion channels is the potassium ion channel. The potassium ion ...
Voltage-gated ion-channels are usually ion-specific, and channels specific to sodium (Na +), potassium (K +), calcium (Ca 2+), and chloride (Cl −) ions have been identified. [1] The opening and closing of the channels are triggered by changing ion concentration, and hence charge gradient, between the sides of the cell membrane. [2]
Here is a hand-drawn depiction of a membrane bound sodium-potassium pump and sodium and potassium ion channels can be seen along with the directed movement of the ions indicated by arrows. The sodium-potassium pump works with the sodium and potassium leak channels to maintain the membrane potential between the cell and the extracellular space ...
Carrier and channel ionophores (a) Carrier ionophores reversibly bind ions and carry them through cell membranes. (b) Channel ionophores create channels within cell membranes to facilitate the transport of ions. In chemistry, an ionophore (from Greek ion and -phore 'ion carrier') is a chemical species that reversibly binds ions. [1]