Lauren H. answered • 08/31/18
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physiological saline contains 0.154 moles of NaCl per liter.
300 millimolar solution of NACL x 1 mole/1000 millimoles = 0.30 moles/L
water will rush out of the cells and they will crenate.
( You can't change the molarity of NaCl inside the cell. Enzymes won't work...)
Naillah H.
I still don’t understand
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08/31/18
J.R. S.
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The hyper and hypo has to have some reference. If the cell is mammalian, then the reference is 154 mM, and 300 mM is hyper. If the cell were to be something from outer space, where the normal environment was, say, 500 mM NaCl, then the 300 mM would be hypo. Typically, we are dealing with mammalian cells or some cells from some other species, but 300 mM NaCl is generally considered to be hyper osmotic. But to answer your question, NO, you cannot think of it as higher than 300 mM is hyper and less than 300 mM is hypotonic. Also, a final word of caution. Osmolarity considers both penetrating and no-penetrating solutes, whereas tonicity considers only non-penetrating solutes. NaCl (Na+ and Cl- ions) are non-penetrating so we should correctly be speaking about hyper and hypo tonic and not hyper and hypo osmotic. Hopefully this helps you understand Lauren's answer.
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09/01/18
Naillah H.
08/31/18