Final answer:
Secondary active transport uses the energy of the electrochemical gradient established by primary active transport to move material across the cell membrane.
Step-by-step explanation:
Secondary active transport uses the energy of the electrochemical gradient established by primary active transport to move material across the cell membrane. This process does not directly require ATP, but it still requires energy. For example, sodium ions are transported into the cell through membrane channels, using the electrochemical gradient created by primary active transport. Many substances, such as amino acids and glucose, can be brought into the cell through secondary active transport.