Who proposed the concept of the unit membrane for the tripartite structure?

The main structural component of the plasma membrane of various cellular organelles is:

The cell membrane is composed of .........

What is the name of the current model for the cell membrane proposed by $Singer$ and $Nicolson$?

In the structure of the cell membrane,$........$ is essential,and in determining the permeability of the cell membrane,$........$ mineral element is important.

In terms of permeability,the cell wall and plasmalemma are: