Question

1) Answer the following questions:

a) Explain a concentration gradient using K⁺, Na⁺, and Cl^-.

b) I have a nerve cell and sodium channels are blocked. What happens when potassium rushed out of the cell?

Answer 1

A) The Na⁺/K⁺ Pump creates a concentration gradient by moving 3 Na+ out of the cell and 2 K⁺ into the cell.

the pump continues to move Na⁺ out of the cell even when more Na⁺ions are present there.   In other words, Na⁺ is being pumped (and K⁺ in) against their concentration gradients.

Because this pump is moving ions against their concentration gradients it requires energy in the form of ATP.

B) The cell will become HYPERPOLARISED. Hyperpolarization is when the membrane potential becomes more negative at a particular spot on the neuron’s membrane. This means that the interior of the cell is negatively charged relative to the outside.While hyperpolarized, the neuron is in a refractory period that lasts roughly 2 milliseconds, during which the neuron is unable to generate subsequent action potentials.