LIFESCI 3 Chapter Notes - Chapter 12.2: Doxorubicin, Cyclobutane, Exonuclease
Document Summary
Water is involved in spontaneous hydrolysis reactions that damage nucleotides and the. Negative charge on dna prone to electrophilic attack by alkylating agents and reactive oxygen species. Radiation can cause chemical changes in dna. Chemicals can directly damage dna or are metabolized to dna-damaging agents. Spontaneous dna damage by water can cause point mutations. Hydrolysis: cleavage of a molecule by the addition of water. Initiated by nucleophilic attack by a hydroxide ion. Leaving group acquires a proton giving a net addition of water to the substrate. At physiological ph, [oh-] is low so hydrolysis is slow. Large # of nucleotides damage at a slow rate adds up to be significant. Deamination: removal of an amino group from a compound. Cytosine, adenine, and guanine each contain an amino group. Unrepaired next round of replication would insert thymine changing c-g to a-t.
