State 3 reasons why ion specific channels that allow the pas

State 3 reasons why ion specific channels that allow the passage of Na+, K+ and Cl- across biological membranes are important.

Solution

Ion channel creates a pathway for charged ions from dissolved salts, including sodium, potassium, calcium, and chloride ions, to pass through the otherwise impermeant lipid cell membrane. Ion channels are important because:

1. Ions are generally way too large to diffuse through the membrane. Channels show ion selectivity, permitting some inorganic ions to pass, but not others. This suggests that their pores must be narrow enough in places to force permeating ions into intimate contact with the walls of the channel so that only ions of appropriate size and charge can pass.

2. Ions can\'t diffuse through hydrophobic cell membrane because they have negative or positive charge. Ion channels help to carry these ions upto cell membrane. Ion channels are not continuously open. Instead, they are gated, which allows them to open briefly and then close again. In most cases, the gate opens in response to a specific stimulus. The main types of stimuli that are known to cause ion channels to open are a change in the voltage across the membrane (voltage-gated channels), a mechanical stress (mechanically gated channels), or the binding of a ligand (ligand-gated channels).

3. During the transport, ions necessarily bind to selective carrier proteins which is removed before transport into he cell.

4. Ion channels are key molecules for signal transduction across biological membranes. Combining physiological experiments with DNA sequence data has recently linked many diseases to defects in ion channels and, to acknowledge this, the term ‘channelopathies’ has been coined.