Tetrodotoxin (TTX) is a chemical found in pufferfish which binds to voltage-gated sodium channels causing inactivation via a conformational change. Poisoning can result in paralysis leading to death. How might this occur? (4 marks)

This question asks about nerve action potential generation. There are a couple of clues - these include 'voltage-gated sodium channels' and 'paralysis' which suggests the idea of failure of impulse transmission along a neurone. Answering this question requires a good understanding of the different processes which occur during an action potential.A model answer would be: TTX blocks voltage-gated Na+ channels preventing an influx of sodium when the membrane is depolarised (by a generator potential) [1]. This prevents the rapid rising limb of the action potential from occurring [1] so that an impulse can no longer be transmitted along the neurone [1]. As a result, no neurotransmitter is released at the terminal/neuromuscular junction [1] and muscles cannot be stimulated to contract.There may be other structured parts to this question. For example: death is usually caused by respiratory failure resulting from the paralysis of the diaphragm - why does this result in death?

Answered by Rafee A. Biology tutor

3166 Views

See similar Biology A Level tutors

Related Biology A Level answers

All answers ▸

Why do mutations makes it difficult to create a vaccine ? (4 marks - has the potential to be worth more in an exam)


State 3 organelles found in a Eukaryotic cell and the functions of each organelle.


Explain how an electrochemical gradient is formed in the mitochondria, and how this gradient is used to synthesise ATP.


Describe the process of transcription


We're here to help

contact us iconContact usWhatsapp logoMessage us on Whatsapptelephone icon+44 (0) 203 773 6020
Facebook logoInstagram logoLinkedIn logo

© MyTutorWeb Ltd 2013–2024

Terms & Conditions|Privacy Policy
Cookie Preferences