5) Loss of the 3' to 5' exonuclease activity of DNA polymerase in E. coli should slow the rate of DNA synthesis but not affect its fidelity.

13. Describe the figure below. Note: it starts from amino acids. What are the diseases associated with it? How does one deal with the diseases? Can the urea cycle work alone? What are the roles of oxaloacetate? What does the cell do when oxaloacetate is used up by the urea cycle? (8%)