the properties of the d-glucose transport system of zymomonas mobilis were determined by measuring the uptake of nonmetabolizable analogs ( 2-deoxy-d-glucose and d-xylose ) by wild-type cells and the uptake of d-glucose itself by a mutant lacking glucokinase . d-glucose was transported by a constitutive , stereospecific , carrier-mediated facilitated diffusion system , whereby its intracellular concentration quickly reached a plateau close to but not above the external concentration . d-xylose was transported by the d-glucose system , as evidenced by inhibition of its uptake by d-glucose . d-fructose was not an efficient competitive inhibitor of d-glucose uptake , indicating that it has a low affinity for the d-glucose transport system .
C0007634
cells
C2244328
facilitated diffusion