first of all since phenol is immiscible in water it forms the basis for phase separation, being heavier it settles down, but when water and phenol are mixed by vortexing, phenol droplets enter into water and denature the proteins by changing its folding pattern, whereas choloform assists more in separation being a dense oganic solvent.
The link attached will futher clarify your doubts!!
first of all since phenol is immiscible in water it forms the basis for phase separation, being heavier it settles down, but when water and phenol are mixed by vortexing, phenol droplets enter into water and denature the proteins by changing its folding pattern, whereas choloform assists more in separation being a dense oganic solvent.
The link attached will futher clarify your doubts!!