Xiaoxiao chen MCB 184 labBase Pairing 21.Adenine has amino group and Hypoxanthine has carboxyl group and has one more hydrogen bonding with nitrogen. The amino group of adenine interact with water cause a deamination event. The outcome of the deamination event to convert adenine into hypoxanthine.2. The original of fCyt Taut is Cyt that should be pair with Gua. The reason why G and C can go together is that the three candidate positions from top to bottom on G structure are negative, positive and positive and the three candidate positions from top to bottom on C structure are positive, negative and negative. So their charges allow them to form three hydrogen bonds. The tautomer of Cyt pair with adenine because the three candidate positions from top to bottom on the tautomer of Cyt are negative, positive and negative, but three candidate positions from top to bottom on the Adenine are positive, negative and the last one position has no charge because hydrogen bond with carbon So two hydrogen bonds form between tautomer of Cyt and Adenine.The tautomer could be dangerous because it has mutated and it is not its actual place in the Baisepairing3. 1) Amino group of Cytosine can make interact with water molecule cause a deamination even. The outcome of event is to convert Cytosine to Uracil. 2) NO, This process of cytosine deamination still happen in DNA.3) When the Uracil sits where cytosine should be, this mistake will be corrected before DNA replication by several enzymes. These enzymes can recognize Uracil and cut it out of the DNA. Enzyme are to remove uracils: Uracil-N-glycosides, enzyme are to clean up positions whose base is missing b/c of action of UNG and enzyme to de-activate dUTP created by cell’s normal deoxy creation process. In a code of AGCT, the appearance of a U is novel and stands out; it means that the result of a deamination event is detectable and thus can be acted upon.4）Mutation is inevitable because the protein or DNA are exposed to water and this leads to mutation like dream inaction. These mutations can be caused by environmental factors such as ultraviolet radiation, or can occur if a mistake is made when DNA copies itself. For example, in pairing of G and T, their charges at the first interaction points show negative and negative. Their charges at the second interaction show positive and positive.So they cannot form hydrogen bonds. There is a potential hydrogen interaction betweenG and T, but it does not happen because hydrogen donor at the right bottom of G structure is far away from the hydrogen acceptor of left bottom of T structure. The length of hydrogen bond is too short to connect them. But when G is snapped in to tautomer, From top to bottom on the fGuaTaut, three candidate position shows positive, negative and positive. From top to bottom on the Thy, three candidate positions show negative, positive and negative. So charges allow them can form three hydrogen bonds. G and T cannot be a pairing, but fGuaTaut and Thy can be a pairing, therefore, this change cause achange in store information of a molecule of DNA can occur. 5）This type of mutation will present throughout a person’s life in every cell in the body. 6) If the DNA in one of the skin cells were to change, the change is called Acquired mutations will occur on the in the DNA of individual cells at some time during a person’s life. And acquired mutations in the somatic cells cannot be inherited to next