ion channels

Ion channel

An ion channel is a transmembrane with a hole in it. It allows the passage of ions across the cell membrane. Ions are passively transported across the cell membrane down their concentration gradient ​

Types of ion channels

Voltage - gated ion channels

• Have high selectivity for one ion over all other

• Rates of opening and closing can vary considerably

• Mechanism of inactivation (closing) may also be voltage dependent

• 3 types : sodium, potassium, calcium

Ligand - gated ion channels

• Are both receptors and ion channels

• Essential for fast synaptic transmission

• Binding of a neurotransmitter generates ire confrontational change in protein to open integral ion channel

Transient receptor potential channels

• Mechanisms of activation (opening) are wide ranging

• Can be poly modal

• involved in sensing the external and internal environment