And so we conclude that a membrane with strong intermolecular interactions will have a higher melting temperature than a membrane with weaker ones. So again, a stronger or stronger interactions basically implies a more rigid, more well defined and ordered structure and that implies a higher melting temperature. Now, we know that membrane fluidity is determined by the relative movement of those lipids and the other molecules in the membrane. And the relative movement is determined by the strength of those inter molecular interactions. But what determines the strength of those intermolecular interactions within the membrane? Well, three things.