Sucrose is a distinct molecule which has the molecular formula: C12H22O11. It is correct that regardless of source, if it is uniform in its purity, a particle of sucrose will always have 12 carbon atoms, 22 hydrogen atoms and 11 oxygen atoms which are arranged such that the sucrose structure is consistent with that of a disaccharide (two sugar molecules) consisting of one molecule of glucose bound to one molecule of fructose. So the composition of both will be the same.