Question #44984

During DNA replication at $298\text{ K}$, Thymine ($T$) typically exists in the lactam (keto) form and pairs with Adenine. However, a spontaneous point mutation can occur if $T$ undergoes tautomerization to its rare lactim (enol) form ($T^*$), where the proton from N3 migrates to O4. In this $T^*$ form, it mispairs with a different standard nitrogenous base $Y$ from the nucleotide pool.

Given that the $pK_a$ of the N3-H proton in standard Thymine is $9.8$, determine the following four parameters in order:

1. The identity of the mispaired base $Y$.
2. The total number of hydrogen bonds formed in the $T^* \equiv Y$ base pair.
3. The number of hydrogen bond DONORS provided specifically by $T^*$ in this base pair.
4. The net charge on the dominant species of standard Thymine at an alkaline pH of $11.8$.