blue Fehling solution turns red by sugar

Fo05 Digestion: Starch is transformed into sugar

"Well chewed means half digested":
* Leave your saliva of the previous experiment  to act
   on the chewed potato.
* Photo: Heat 0.5 ml of this liquid together with one drop of a blue  Fehling solution.
Observation (photo, right vial: The blue solution has changed into a brick red precipitation.
 Explanation:  Starch of the potato was digested by the saliva leaving a sugar which reacted with Fehling solution.

back....... go on.................................................................................................last modification: 08.10.2001