Question

A passive transporter is discovered that can transport both galactose and glucose. The pore of the transporter can accommodate a single sugar at a time. If the extracellular concentrations of galactose and glucose are 0.25 and 4.0 mM, respectively, and the intracellular concentrations are 0.4 and 3.0 mM, respectively, which sugar is most likely to enter the cell through the transporter? Provide two reasons for your answer.

Answer 1

In passive transport the molecules are transported without the use of energy.in this molecules move down the concentration gradient which is formed across the membrane.

So the transporter will move glucose molecules into the cell as its concentration is low inside the cell as compared to extracellular glucose concentration.

If it transports galactose then the energy will be required as that will move against the concentration gradient.

Galactose concentration is already higher in the cell .

So through passive diffusion glucose transport will take place