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You are working with a neurotransmitter that, when bound to its receptor, will o

ID: 3474823 • Letter: Y

Question

You are working with a neurotransmitter that, when bound to its receptor, will open Cl^- channels in the cell membrane of nerve cells. The extracellular Cl^- concentration is 0.1 M, the intracellular Cl^- concentration is 0.01 M, and the equilibrium potential for Cl^- is -61 mV, and the resting membrane potential is - 55 mV. When the neurotransmitter binds its receptor and the Cl^- channels open... a) Which direction (into or out of the cell) will Cl^- flow, if acted on ONLY by its concentration gradient? h) Which direction (into or out of the cell) will Cl^- flow, if acted on ONLY by its electrical gradient? c) Which direction will Cl^- flow, if acted on by BOTH gradients (which gradient is stronger and how did you determine this)? How will this change the resting membrane potential?

Explanation / Answer

a) Outside to inside (higher to lower)

b) INside to outside

c) outisde to inside, the membrane potential will become more negative