Tetrodotoxin-Channels and Action Potentials by Louisa Quek

Ion channels - Ions traverse the plasma membrane of cells through channels. - These channels are in fact embedded transmembrane proteins. - Sodium (Na) channels are voltage gated channels, which can be opened or closed in response to changes in charge across the plasma membrane. - These voltage gated sodium channels are crucial for the flow of action potentials in excitable membranes. - The diagram on the right depicts a sodium channel, and the orange filled circles represent tetrodotoxin (TTX) binding sites.
	"voltage gated sodium channels"

Action Potentials - Action potentials, involving the passage of Na+ ions and K+ ions along nerve cell membranes, are electrical messages sent out by the brain to various parts of the body to instruct them on the appropriate action to perform. - The flow of the Na+ ions into the nerve cell is an essential step in the conduction of action potential in nerve fibers and along axons. - The Na+ ions flow through the cellular membrane via the Na channels. - As a result of the influx of Na+ ions, the cell membrane depolarizes and the nerve impulses continue traveling towards the target muscle cells.
	"Action potential"