On the contrary, it's very much a fluidlike structure. In fact, the viscosity of the membrane is very much like olive oil. It's about 100 times more viscous than water. Now, the question is, why is this the case? Well, because of phenomenon known as lateral diffusion. And what that means is the molecules that constitute the phospholipids and in many cases, the proteins that constitute the membrane are actually in a constant state of horizontal lateral emotion.