Resting channels are ion channels in the plasma membrane of a cell that remain open at all times. Also called leakage channels or leak channels, resting channels allow ions to cross the membrane down their electrochemical gradient whether or not the cell is depolarized. This is in contrast to gated channels which may be either voltage-gated, ligand-gated, or stretch-gated. Unlike gated channels, which have two or three conformational states (resting, active, and sometimes inactivated), resting channels have only the open state. Ion channels are pore-forming proteins that help to establish and control the small voltage gradient that exists across the plasma membrane of all living cells (see cell potential) by allowing the flow of ions down their electrochemical gradient. ... Drawing of a cell membrane A component of every biological cell, the cell membrane (or plasma membrane) is a thin and structured bilayer of phospholipid and protein molecules that envelopes the cell. ... Cells in culture, stained for keratin (red) and DNA (green). ... An ion is an atom, group of atoms, or subatomic particle that normally is electrically neutral and achieve their status as an ion by loss (and addition) of an electron. ... Electrochemical gradients in cellular biology refers to the electrical and chemical properties across a membrane. ... In biology, depolarization is the event a cell undergoes when its membrane potential grows more positive with respect to the extracellular solution. ... Voltage-gated ion channel is a ion channel that is specifically activated, or gated, by the surrounding potential difference near the channel (or near the cell, neuron or synapse). ... Ligand-gated ion channel is a broad term that refers to any ion channel that is gated (i. ... Stretch-activated or stretch-gated ion channels are ion channels which open their pores in response to mechanical deformation of a neurons plasma membrane. ...

In neurons, resting channels contribute to the negative resting membrane potential in by allowing positively-charged potassium ions to flow out of and negatively-charged chloride ions to flow in to the cell down their electrochemical gradients. Since there are fewer resting sodium channels than there are resting potassium and chloride channels, this causes a net efflux of positive charge, making the resting membrane potential hyperpolarized, or negative. This continuous flow of ions is known as a "leak current". Leak currents are much smaller than currents flowing through voltage-gated ion channels. Neurons (also called nerve cells) are the primary cells of the nervous system. ... Membrane potential (or transmembrane potential or transmembrane potential difference or transmembrane potential gradient), is the electrical potential difference (voltage) across a cells plasma membrane. ... General Name, Symbol, Number potassium, K, 19 Chemical series alkali metals Group, Period, Block 1, 4, s Appearance silvery white Atomic mass 39. ... The chloride ion is formed when the element chlorine picks up one electron to form an anion (negatively-charged ion) Cl−. The salts of hydrochloric acid HCl contain chloride ions and are also called chlorides. ... Electrochemical gradients in cellular biology refers to the electrical and chemical properties across a membrane. ... General Name, Symbol, Number sodium, Na, 11 Chemical series alkali metals Group, Period, Block 1, 3, s Appearance silvery white Atomic mass 22. ... Hyperpolarization has several meanings: In biology, hyperpolarization occurs when a cells membrane potential dips below its resting level. ...

Resting potassium channels are thought to lack the S4 voltage-sensing region (discussed in the article on sodium channels) which confers the ability to change configuration in response to changes in transmembrane potential (Karp, 2005). In cell biology, potassium channels are the most common type of ion channel. ... Sodium channels are integral membrane proteins that exist in a cells plasma membrane and regulate the flow of sodium (Na+) ions into it. ... In membrane biophysics sometimes used interchangeably with cell potential, but applicable to any lipid bilayer or membrane. ...

References

• Hille, B. 2001. Ion Channels of Excitable Membranes, Third ed. Sinauer, Sunderland, MA.
• Kandel ER, Schwartz JH, Jessell TM. Principles of Neural Science, 4th ed., pp.106, 129-131. McGraw-Hill, New York (2000). ISBN 0-8385-7701-6
• Karp G. 2005. Cell and Molecular Biology: Concepts and Experiments, Fourth ed, p. 167. John Wiley and Sons, Hoboken, NJ.