Final answer:
Glucose can be transported through both GLUT transporters via facilitated diffusion and SGLT transporters via secondary active transport, which utilizes the sodium ion gradient. The existence of both methods allows efficient glucose uptake across different concentration gradients and conditions.
Step-by-step explanation:
Glucose can move across the cell membrane using different types of transporters such as GLUT transporters and SGLT transporters.
GLUT transporters facilitate the passive movement of glucose across the cell membrane through a process called facilitated diffusion. This process does not require energy as it occurs down the glucose concentration gradient.
On the other hand, SGLT transporters use a process called secondary active transport, often in the kidneys and small intestine. They move glucose against its concentration gradient by coupling its transport with the movement of sodium ions, which moves down its electrochemical gradient established by Na+/K+ ATPases.
The primary distinction between the two is that facilitated diffusion does not require external energy, while secondary active transport indirectly utilizes energy by exploiting the sodium ion gradient. The physiological advantage of having both processes is that facilitated diffusion allows for glucose uptake without energy expenditure when glucose concentration is higher outside the cell, while secondary active transport enables glucose uptake even when its concentration is lower outside the cell or in the lumen of tubules in the case of kidneys.