Polarized light passing through a sugar solution is rotated. A polarimeter allow
ID: 909217 • Letter: P
Question
Polarized light passing through a sugar solution is rotated. A polarimeter allows us to measure the size and direction of the rotation. A freshly prepared solution of a-D-glucose shows a specific rotation of +112 °. Overtime the rotation of the solution decreases and reaches an equilibrium of specific rotation of +52.5 °. In contrast, a freshly prepared solution of b-D-glucose shows a specific rotation of +19 °. The rotation of this solution increases overtime to the same value as that shown by the a anomer.
Calculate the ratio between a-D-glucose and b-D-glucose at the equilibrium.
The glucose oxidase assay used to determine blood glucose level only detects the concentration of b-D-glucose. The normal blood glucose level is 70 to 150 mg/L. If the assay shows the b-D-glucose concentration of a patient’s is 140 mg/L, what is the overall glucose level of the patient? Could this patient be diabetic?
Explanation / Answer
Polarized light passing through a sugar solution is rotated. A polarimeter allow