What is required to break covalent bonds in glucose? Im thinking of ATP and Enzymes but Im not sure.

http://books.google.com/books?id=Ugt1_4FxmgAC&pg=PA141&lpg=PA141&dq=break+bonds+in+glucose&source=web&ots=pr7w5oMShW&sig=c9g63v95VvY8hIPMswda3ijw_aY&hl=en&sa=X&oi=book_result&resnum=2&ct=result