Final answer:
The reason it takes longer to bake a whole potato than cut potatoes is due to the difference in starch content. Starchy potatoes, which are better for baking, have unbranched polymers of glucose as their starch, while waxy potatoes, better for retaining shape, have branched polymers.
Step-by-step explanation:
The reason it takes longer to bake a whole potato than potatoes that have been cut into pieces is because of the difference in the type of starch present in each. Starchy potatoes have almost all of their starch as unbranched polymers of glucose, which makes them better suited for baking. On the other hand, waxy potatoes have a greater portion of their starch existing as branched polymers of glucose, allowing them to retain their shape even after cooking. Therefore, whole starchy potatoes take longer to cook than cut waxy potatoes.