Which of the following sugars is NOT classified as a simple sugar that can be directly absorbed from the digestive tract in humans?
A. Fructose.
B. Glucose.
C. Glycogen.
D. Galactose.
Fructose, glucose, and galactose are all simple sugars derived from hydrolytic cleavage of polysaccharides and double sugars. These simple sugars are then readily absorbed from the digestive tract. Glycogen is the storage form of glucose in the different cells of the body.