Question

The following image represents the membrane of a human neuron.
At rest, a human neuron has a membrane potential of -70mV. Based on this image, which of the following statements best explains how the negative membrane potential is generated?

Answer 1

post the image please?

Answer 2

A. The lipid bilayer is highly permeable to potassium ions but semipermeable to sodium ions, allowing a greater outflow of positive potassium ions than inflow of negative sodium ions.

B. The potassium channels transfer four potassium ions out while the sodium channels transfer two sodium ions in, resulting in a net outflow of positive potassium ions.

C.The presence of more potassium channels than sodium channels in the membrane results in a net outflow of positive potassium ions.

D. The sodium-potassium pumps and sodium channels require ATP to transfer ions, but the potassium channels transfer ions through facilitated diffusion, resulting in a net outflow of potassium ions.

Answer 3

Simple answer: The Cl- (negatively charged) ions are pumped in from outside the neuron to keep a negative potential at rest.

(If you're asking about the actual signal: Since the RESTING potential is negative (caused by Cl- ions), it would make sense that a signal is generated by a positive charge. The positive charge is caused by Na+ ions flowing INTO the neuron, and Cl- ions flowing OUT of the neuron, through pumps/channels.)

Answer 4

So would the answer be C?

Answer 5

Looking at the picture right now. A lot of K+ goes out through the channels, and a little go in through the pump. Na+ both comes in and goes out. So I think the answer is D.

Answer 6

Thanks!