What is the structural formula of carbohydrates?I am so confused. I searched for this answer many times, and I always find a different answer....

Carbohydrates, as the name imples, are composed of carbon and water.  The empirical formula for most of them is:

Cx(H2O)y

where x and y are integer numbers of carbon atoms and water molecules, although some carbohydrates deviate from the strict hydrogen to oxygen ratio.   Most carbohydrates have the suffix -ose on the end of their names, and this large class of molecules includes sugars, starches, and cellulose, and are components of DNA, RNA, and ATP.  The most common carbohydrate is the sugar glucose, which has a structural formula of C6H12O6

Encyclopedia Britannica, 11th ed., vol. 5, pg. 304.