Because flours are manufactured through the grinding of dried wheat grass grains into a fine powder, there is no one chemical formula for all types of flour. However, it can be most easily deduced that flour will contain the same chemical components as the grass from which it was made.
The largest contributor to the mass of commercial flours is a special type of sugar called starch. In wheat, starch serves as a structural component, allowing the grass to grow tall and to bend in the wind. The second largest component of flour is wheat protein, which gives different types of flour its properties that lead to chewyness or softness of baked breads.