The effect is due to the chirality of the molecules .
Indeed the mirror - image isomer , L - ( - ) glucose , is levorotatory ( rotates polarized light counterclockwise ) by the same amount .
The effect is due to the chirality of the molecules , and indeed the mirror - image isomer , L - ( - ) glucose , is levorotatory ( rotates polarized light counterclockwise ) by the same amount .