What is the structure of the molecules?
The molecular structure shows that the molecule has a positively charged amine group which can then bond to the carboxylate groups on the side chains in the mouth of the sodium channel, blocking it. The bond forms due to the electrostatic attraction between the positively charged guanidine group and negatively charged carboxylate groups, forming a strong ionic bond. The bond means that a large amount of energy is required to overcome the attraction and break the bond, unblocking the channel. The molecule below is also relatively small in size, allowing the molecule to utilise a carrier protein in facilitated diffusion to move into the epithelial cell and the bloodstream where it can affect the target organ, the nervous system. The molecule has the potential react with biological molecules especially when concerning the charged oxygen and guanidine groups as well as the polar hydroxyl and amine groups, formed by the large difference in electronegativity. Electronegativity is the measure of the ability of an atom in a covalent bond to pull electrons towards itself, forming regions of high negative electron density by the most electronegative atom while the less electronegative atom gains a positive delta charge. This means that this is a highly reactive species and has the potential to react with biomolecules, causing potentially fatal disruptions to the cell on a molecular level. However, the nature of this molecule means that it generally targets the nervous system specifically sodium release channels. Molecules with target organs can be highly effective poisons if the target organ requires a low dosage to cause adverse effects to the organ, the organ has a low rate of removal and if the organ is seen as crucial to survival.