The botulinum toxin (or Botox) is one of the most lethal toxin to humans with a killing dose of 1 ng/kg of bodyweight. In order to have a better understanding of the potential molecular mechanism, estimate how many molecules of Botox are necessary to kill a single human cell. You will, as usual, state your rationale and explain your calculations. You can use the internet to get access to useful numbers on the botulinum toxin.