Question

 What happens in cyclization process of glucose and why is the straight form of glucose more reactive than the ring/cyclic form?

Answer 1

Cyclization of glucose to its hemiacetal form Glucose has an aldehyde group and five hydroxyl groups.In the case of glucose, a 6-membered ring is thermodynamically more stable than a 5-membered ring, thus favoring the formation of a 6-membered ring over a 5-membered ring