One wouldn’t allow for passive transport. And the other would allow to much. The membrane serves as a gate. Non-permeable would be a solid wall were nothing and no one can get through or get out . Including things like water. And fully permeable would represent no gate at all and would allow to much in and out of the cell.
What do you mean by responsible? Do you want to know the genetics behind it, what the surface markers do, or why they are metically important? I think I can help.
CH3- methyl group
COOH- carboxyl group
H2O- just water
NH2- amino goup
OH- hydroxyl group
the answer is H2O
There are two hydrogen atoms in a molecule of water.
