Why does the cell membrane need proteins embedded in it?

Transporter or Carrier Proteins. They are embedded in the cell membrane to help transport glucose and amino acids across the membrane. They are too large to go through ion channels.

Explanation:

the answer that best describes the relative refractory period in the neuron is the resting membrane potential is restored, but concentrations of sodium and potassium are not restored to their original state.

the refractory period is the time during which another stimulus given to the neuron will not lead to a second potential. thus, because na+ channels are inactivated during this time, additional depolarizing stimuli do not lead to new action potentials.  

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