BIOLOGY 152 Lecture Notes - Lecture 7: Voltage-Gated Potassium Channel, Tetraodontidae, Tetrodotoxin

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cerisebuffalo390

1 Mar 2016

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Bio152 lecture 7 action potentials and applications. Voltage-gated ion channels: na+ a fast opening gate a slow closing gate, k+ a slow opening gate. Voltage-gated ion channels and diffusion: remember: there are negatively charged macromolecules that cannot move in, once the channel opens, ions follow chemical and electrical gradients and out. Stages of action potential: resting state, threshold, depolarization phase of action potential, repolarization phase of action potential, undershoot, back to resting state. In the liver of the puffer fish, and throughout it"s tissues, has a toxin called tetrodotoxin. Tetrodotoxin immunity: small random changes to the shape of ion channel keep toxin from blocking the channel. Individuals with changed ion channels have a higher probability of surviving and pass that change on: oddly, the same changes occur in a diverse and evolutionarily distant related groups of animals, evolution can repeat itself!

Related Questions

What would be most strongly affected by a drug that inhibited the opening of voltage-gated potassium channels (also known as delayed rectifiers)?

A. Falling phase of an action potential

B. Rising phase of an action potential

C. Resting membrane potential

D. Threshold for an action potential

Why does the voltage during the undershoot phase of the action potential become more negative than the resting membrane potential?

A. During the undershoot potassium ions are flowing into the cell due to the reversal of the potassium concentration gradient occurring during the action potential

B. The undershoot phase results from a delay in the activation of sodium channels, resulting in some sodium channels being open after the voltage-gated potassium channels have closed. C. The potassium conductance is higher during the undershoot than during the resting membrane potential.

D. The concentration gradient for potassium has been reversed as a result of the action potential, and the undershoot phase lasts until this the concentration gradient is restored.

silverdinosaur935

In order for Neurons to communicate, Resting Membrane Potential must CHANGE. Examples of changes in Membrane Potential included Graded Potentials and Action Potentials. In order for there to be a change in membrane potential, ions must move across the plasma membrane. There are THREE Primary types of Ion Channels: Passive (Leak) Channels, Voltage-gated Channels and Chemically-gated Channels.

DIRECTIONS

Indicate which voltage-gated channels are functioning during each phase of an Action Potential

skyhorse437

DIRECTIONS

Select ONE type of Ion Channel and indicate whether that Ion Channel is MOST important for producing Resting Membrane Potential, Graded Potentials or Action Potentials. Provide detailed support for your choice.

purpleweasel693

BIOLOGY 152 Lecture Notes - Lecture 7: Voltage-Gated Potassium Channel, Tetraodontidae, Tetrodotoxin

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