A ketohexose is a simple carbohydrate with six carbon atoms as well as a ketone group which islocated on the second carbon atom. It is the sweetest of the simple carbohydrates and is produced along with glucose when sucrose is hydrolyzed. It is found in fruit, honey, and other parts of plants.
All simple carbohydrates have the same chemical formula, C6H12O6 but they differ with their orientation of the hydroxyl groups on the chiral carbons relative to the other carbons and whether they have an aldehyde (on the first carbon) or a ketone (on the second carbon).
Fructose the most water soluble simple carbohydrate and one of only three that can pass directly into the blood stream.