Here in the forum I seem to learn more from the discussions. Thanks guys. The cell membrane must be working around the clock. It must get 'tired' working this hard, if not the cell dies. And if it dies, there must be some new reproduction of cells. I believe.

how does the cell membrane distinguish materials entering into the cell?

How does the cell know which substances are harmful?

How do harmful substances enter the cell membrane?

I wonder why water is allowed to flow freely through the membrane as opposed to other substances? Interesting stuff!

Cell membrane audio is not working

How does the cell membrane destinguish between substances? Is it size based?

Cell membranes help organisms  by controlling what substance may enter or leave cells

Why harmful substances can't enter the Cell membrane through the channels which it has for their removal?

is the cell membrane the same as the plasma membrane?