Pufferfish (Fugu) are a delicacy in Japan, but must be cleaned very carefully as

Question

Pufferfish (Fugu) are a delicacy in Japan, but must be cleaned very carefully as their liver contains tetrodotoxin which blocks voltage-gated Nat channels. Imagine you are testing for the presence of this toxin using a neuron in a dish. You apply an electrical stimulus to the neuron that should produce an action potential. What will you observe if tetrodotoxin levels are high enough to block the neuron's voltage-gated Na+ channels? The neuron will exhibit a slow depolarization even before the stimulus is applied, followed by a normal action potential. O The neuron will exhibit a slow hyperpolarization even before the stimulus is applied The neuron will show a normal resting potential, but will not exhibit depolarization when the stimulus is applied The neuron will exhibit rapid depolarization, but will not repolarize. The neuron will depolarize normally, but then become hyperpolarized such that the membrane potential is much lower than usual. 10 pts Question 2 A graded hyperpolarization of a membrane can be induced by O increasing its membrane's permeability to Na+ O decreasing its membrane's permeability to H+ O decreasing its membrane's permeability to Cl increasing its membrane's permeability to Ca2+

Explanation / Answer

1Q). the correct answer is 3rd option.

the neuron will show a normal resting potential, but will not exhibit depolarization when the stimulus is applied.

Tetrodotoxin is a neurotoxin that binds to TTX-s Na+ channels with a binding affinity of 5–15 nM, while the TTX-r Na+ channels bind TTX with low micromolar affinity. It inhibits the initiation of action potentials in neurons by binding to the sodium channels in membranes of nerve cells and blocks the passage of Na+ ions. This toxin attach the Nerve cells of cardiac tissue contains TTX-r Na+ channels, next spread all over the body.

2Q). increasing its membrane's permeability to K+.

please post the remaining questions separately (chegg rule) thank you

Related Questions

Navigate

• Browse (All)
• Browse P
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.