Question

Questions 1. Which of the following contribute to the resting potential (voltage) across a cell membrane? Explain your rationale for each.

A. Extracelluar cations near the membrane

B. Cytosolic anions

C. Negatively charge proteins at the cell cortex

D. Cytosolic cations

Question 2. Explain why it is important to have a coupled transporter in place here and not the carrier protein GLUT-1.

Answer 1

1. Option A, Extracelluar cations near the membrane

Explanation –

A neuron that is non-signaling or resting creates voltage across the membrane termed as resting membrane potential/resting potential. This resting potential is determined by concentration gradients of ions such as Na+ and K+ across the membrane.

These two ions move down their gradients via channels and hence create the resting potential. The variation of membrane potential as compared to the resting potential determines whether the membrane is depolarized or hyperpolarized.