If your body is capable of making only certain amino acids, how do we get the essential amino acids we need? i need quick

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.  

read more on -

because the light is a great source of energy for the plants to survive. (i hope this )