The results for the first wet chemistry test suggested that the martian regolith contained several soluble minerals necessary for life , including potassium , magnesium and chloride .
This uses special membranes which act as molecular sieves by passing water molecules while holding back the ions , such as sodium and chloride , that make water salty .
When the neurotransmitter gaba binds to its receptor , the receptor opens and a flood of negatively charged chloride and bicarbonate ions rush into the cell and prevent it from firing .