Starch is a polysaccharide, meaning molecule that has many, many, many sugar units. And the sugar unit that starch is made up of is glucose. And the glucose is arranged in different fashions depending on their glycosidic bond. And there are subunits of starch called amylose and amylopectin. Here's the molecular structure of starch, a piece of amylose and a piece of amylopectin. You can see what's common between the two of them is they all have the same ring structure connected together. And these ring structures are glucose. And this amylose and amylopectin differ by how the glucose is connected and also amylopectin has branches off the main chain of the glucose polymer. When starch undergoes hydrolysis, all of these linked glucose molecules break up the individual glucose units.