Final answer:
After the dephosphorylation of the critical aspartate residue in the sodium-potassium ATPase, the carrier protein repositions itself inward and then releases the two bound potassium ions into the cytoplasm.
Step-by-step explanation:
During the transport cycle for the sodium-potassium ATPase, the event that occurs immediately after dephosphorylation of the critical aspartate residue is the repositioning of the carrier protein towards the interior of the cell. With the phosphate group removed and potassium ions attached, the carrier protein repositions itself towards the interior of the cell (step 5).
Following this reorientation, the carrier protein, now facing the intracellular space, has a decreased affinity for potassium, which leads to the release of the two bound potassium ions into the cytoplasm. This decrease in affinity for potassium and the concomitant increase in affinity for sodium ions marks the preparation for the next cycle of ion transport (step 6).