need help with cells!!!?

Question

im studying cells in bio 11 and i have a question my teacher couldnt answer me.

the plasma membrane of the cell is composed of phospholipids (fats, proteins and more molecules) and is SEMI-pearmable, which means things can go in and out of the cell, but heres my question:

if a cell membrane were completely permeable, how would this affect the cell?

I would like a lot of info but please keep it simple so a grade 11 could understand it. THIS IS NOT HOMEWORK for the people that will be saying "SO UR QUESTIONG IS "WILL U DO MY HOMEWORK PLEASE?""

Answer 1

If it were completely permeable there would be no difference between its internal environment (which is vital to life) and its external environment (extracellular fluid). It would simply die.

For instance, the cell membrane attempts to throw sodium ions OUT and keep potassium ions IN. As a result, a potential difference of 70 millivots exits across its two faces. That potential difference is the basis of nerve impulses being conducted and muscles being able to contract. Take it away, and those two functions are gone.

In short, all life activity would cease if the membrane became completely permeable.

Answer 2

It won't need to do an active transport of substances within its membrane with macromolecules. Which means it doesn't have the power to keep what it needs from the plasma without being selectively permeable.

Answer 3

To keep it simple, "stuff" that the cell wanted to keep out, wouldn't stay out. It could be something bad that could harm the cell. Also, "stuff" that the cell needed to keep in wouldn't necessarily stay in. It could lose water, nutrients, etc. This would depend on the gradient.

Answer 4

if its completly permeable to many objects would be able to fit inside or leave the cell. i hope i'm thinking about it the same way you are.