Final answer:
Secondary active transport involves the movement of glucose into the cell against its concentration gradient, facilitated by the movement of sodium ions down their gradient using a symporter mechanism.
Step-by-step explanation:
Secondary active transport of glucose is an example of symport, where two transported species are moving in the same direction across the cell membrane. The sodium-glucose symporter is a protein that uses the energy from the flow of sodium ions, which moves down its electrochemical gradient, to transport glucose into the cell against its own gradient. This mechanism relies on the lower sodium concentration inside the cell maintained by the sodium-potassium pump, which actively exports sodium and imports potassium using ATP. Secondary active transport is crucial for processes such as glucose reabsorption in the kidneys, where glucose is moved from the tubular lumen into the cell and eventually into the bloodstream, despite a higher glucose concentration within the cell.