Choose one nuerotransmitter and describe how an external substance effects that neurotransmitter

The proton has a positive charge while the neutron has no charge they both make up the nucleus of the atom while the elections have a negative charge and surround the nucleus of the atom. the protons and electrons are used to calculate the atom's mass whereas the neutrons don't affect the mass

The first means of speeding up reactions mentioned by the speaker is raising the enzymes 

The last option water because it is slow