Do whey proteins precipitate with heat?

I am currently studying about the biochemistry of yoghurt and when reading about the effect of heat in milk proteins specifically whey, my book says that heat can denature whey proteins.


So after the denaturation will the whey proteins coagulate and then peripitate?


If that is the case why in yoghurt that hasn't been homogenized, a layer of whey protein and fat forms on top. For example traditional greek yoghurts all form this top layer because they are left to cool down without any homogenization.


Does the denatured whey proteins go up or down?


