stabe in which it cannot tired either the iding clamp yrsion to this ground state may accur while the bound to the products of ATP hydrolysis (ADP vohsis causes the es to the trigger for ATP hydrolysis. It is critical that trolyze ATP unl a desired complex is asserm- of a particular complex triggers ATP ader, this complex is the loader, and oay require their release. The trel key mechanism to couple ATP hydrolysis to a reac- r cach example below, what will be the result after replication if not repaired? Also naote if it results in a transition or transversion: a. pase pair, an adenine tautomer is placed across from the cytosine during replication ehe compaiene pfree in solutig . ima1:A base pair, the adenine undergoes tautomerization prior to replication C. in a T:A base pair, 5-bromouracil is incorporated across from an adenine prior to replication d. In an A:T base pair, oxoG is placed across from the A during replication aduso patje Why is MutT so important? What occurs in cells lacking this enzyme? although 1 poisomer ding clamp n sliding ing clamp hese DNA uring sev be remo loaders 33. How does DNA polymerase proofreading specifically recognize mispairs (by what mechanism)? 34. Define the roles of each in mismatch repair: MutS, MutL, and MutH, exonuclease 35. How does E. coli distinguish between the old and new strand for mismatch repair? 36. How do human cells distinguish between the old and new strand for mismatch repair? ame tir ap. Thu to rer 37. What are the steps of base excision repair? Where does the glycosylase cleave? aki fra h the amp Et wi 38. Why does the OXOG failsafe system lead to more ATEDOCG than CGeD AT transversions? 39. What are the steps of nucleotide excision repair in bacteria? Why are the bacterial proteins in this pathway named "UV" and human proteins "XP"? 40. Which repair system is tightly coupled to transcription? Why is it important to repair damage sensed by RNA polymerase quickly? 41. What is translesion DNA synthesis and when is it used? Why is it a last resort? Does it repair ssDNA or dsDNA? 42. What are the steps of homologous recombination repair? Which proteins are involved in searching for homologous sequences and how do they function? 43. What are the steps of nonhomologous end joining? 44. When is NHEJ used as a mechanism for DNA repair? Why is it a last resort? Does it repair ssDNA or dsDNA? 45. Describe the general steps needed for a cell to become cancerous. 46. How do mutations and chromosomal abnormalities affect proteins and lead to disease? 47. What role do cell cycle checkpoints have in cancer? 48. Define a tumor suppressor and oncogene and give an example of each. 49. Define the role of ATM in the cell and cancer. Upon/DNA damage, ATM decideş whether to activațe HRR or NHEJ. Which is preferred and why?