Membrane proteins are held in the bilayer mainly by

Which of the following is a selectively permeable membrane?

$A$ boy is studying the transport of a certain type of molecule into a cell. He finds that the transport slows down when the cells are poisoned with a chemical that inhibits energy production. Under normal circumstances,the molecules studied by the boy are probably transported by

In the fluid mosaic model of the plasma membrane:

In the human erythrocyte membrane,the percentage of protein $P$ and lipid $Q$ is respectively:

That the cell membrane is selectively permeable can be best deduced by