A glucose molecule is the

Glucose (C6H12O6) is a hexose -- a monosaccharide containing six carbon atoms. Glucose is an aldehyde contains a -CHO group.

Explanation:

the solute can move "downhill," from regions of higher to lower concentration, relying on the specificity of the protein carrier to pass through the membrane. this process is called passive transport or facilitated diffusion, and does not require energy.