Final answer:
To increase the rate of sucrose transport into the cell, one should consider the active transport mechanisms utilized, which often require ATP. Among the experimental treatments, adding a substance that makes the membrane more permeable to hydrogen ions would most likely increase sucrose transport if the transport is coupled with proton movement.
Step-by-step explanation:
To increase the rate of sucrose transport into the cell, one must consider how the sucrose transport mechanism operates. In general, sucrose transport into the cell involves active transport, which requires energy often in the form of ATP. With this in mind, let's evaluate the experimental treatments listed:
Decreasing extracellular sucrose concentration - This would likely decrease the rate of sucrose transport into the cell by increasing the concentration gradient that sucrose must be transported against.
Decreasing extracellular pH - This can increase the proton concentration outside the cell and could potentially facilitate co-transport mechanisms that pair the downhill movement of protons with the uphill transport of sucrose. However, it could also disrupt other cellular processes.
Decreasing cytoplasmic pH - If sucrose transport is coupled with proton transport, lowering the cytoplasmic pH could theoretically favor co-transport.
Adding an inhibitor that blocks the regeneration of ATP - This would directly inhibit active transport mechanisms that require ATP, thus decreasing the rate of sucrose transport into the cell.
Adding a substance that makes the membrane more permeable to hydrogen ions - This could increase sucrose transport if the transport mechanism involves a proton-sucrose symport system, wherein sucrose transport is coupled with the movement of hydrogen ions.
Based on these considerations, the experimental treatment that would most likely increase the rate of sucrose transport into the cell is adding a substance that makes the membrane more permeable to hydrogen ions (E), assuming that the sucrose transport mechanism involves a symport system with protons.