Final answer:
Primary active transporters directly utilize energy from ATP hydrolysis to move ions across the cell membrane against their electrochemical gradient, setting up the conditions necessary for secondary active transport.
Step-by-step explanation:
Primary active transporters are unique in that they couple the movement of ions directly to ATP hydrolysis. These pumps use energy provided by the hydrolysis of ATP to move substances, such as ions, across the cell membrane against their electrochemical gradient. This process creates a difference in charge across the membrane, essential for maintaining cellular function.
In contrast, secondary active transport does not require ATP directly; rather, it depends on the energy provided by the electrochemical gradient established by primary active transport. Therefore, primary active transport needs to occur first to permit secondary active transport to happen.