Final answer:
The breakdown of starch into sugar in the body is a decomposition reaction, which is Option 1, as it involves the breakdown of complex carbohydrates into simpler glucose units.
Step-by-step explanation:
The process by which starch is broken down into sugar (glucose) in the body is known as a decomposition reaction. This occurs during digestion, where enzymes like salivary amylase and others work to sequentially break down starch into smaller units such as dextrins, maltose, and finally glucose. The enzymes degrade the starch by breaking the glycosidic bonds that hold the glucose monomers together. To better understand the options provided, decomposition refers to a complex molecule breaking down into simpler ones, reversible implies the reaction can proceed in both directions, synthesis means building larger molecules from smaller units, and exchange refers to parts being swapped between molecules.
The correct answer to the question is Option 1: Decomposition. This is because starch is a complex carbohydrate composed of glucose monomers, and during digestion, it is decomposed into the simpler sugar molecules that can be readily used by the body for energy.