<prompt> Answer this question truthfullyWhat happens to DNA synthesis upon bioactivation of 5FU now 5-FdUMP and covalent complex formation with thymidylate synthase and folic acid?  <response>: <reason> DNA synthesis is reduced upon bioactivation of 5FU now 5-FdUMP and covalent complex formation with thymidylate synthase and folic acid. 