ANSC 3301 Lecture 2: 6 February
Document Summary
Voltage-gated sodium channels have 3 conformational states: closed, open and inactivated. Channels transitioning form the open state to the closed state undergo a process called deactivation. In the closed state, channels are unable to conduct ions because of a conformational change in the protein that obstructs ion movement through the channel. The structural element that restricts conduction is typically called the. Activation gate which moves in response to changes in vm, to allow ions to flow through the channel in the open state. Before ions can enter into an ion channel, water molecules surrounding an ion in solution must be removed (more difficult to remove water molecules from smaller ions) It takes more energy to take off water of a sodium ion. Depolarization: membrane voltage moves in a positive direction. Hyperpolarization: membrane voltage moves in a negative direction. No ions moving- membrane voltage should be 0!! Hcn channels in sa node of your heart- drives heartbeat.
