Question

You are studying a neuron from a newly discovered alien species, inside the neuron are many positive charged proteins, P+ Outside the neuron are high concentrations of two negatively charged ions, X- and Y-. Another ion, Z+, also exists both inside and outside the cell (assume the rules of cell membranes, permeability, electric charges and ion channels are the same as a regular neuron on Earth). 1. In its default state, the alien neuoron's membrane is permeable only to Z+.

1.What will happen to the concentration of Z+ inside and outside the cell, and why? What effect will this have on the concentrations of X- and Y- inside and outside the cell?

2. A chemical reaction leads to the opening of ion channels in the membrane for X-. What will happen to the concentration of X- inside and outside the cell, and why? What effect will this have on concentrations of Z+ and Y- inside and outside the cell

Answer 1

1.Z+ concentration will increase outside since it can move through membrane and it moves outside to neutralize the high concentrations of X-, Y- negative ions present outside. The concentration of negatively charged ions X- ,Y- will be reduced .

2. X- will go inside through ion channel to get neutralized by P+, Z+ ions . Y- and Z+ ion concentration will be resuced inside and it will present outside