Question

Draw a structural formula for each nucleotide. (a) \(2^{\prime}\)-Deoxythymidine \(5^{\prime}\)-monophosphate (b) \(2^{\prime}\)-Deoxythymidine \(3^{\prime}\)-monophosphate

Short answer

Answer: The main difference between the structural formulas of 2'-Deoxythymidine 5'-monophosphate and 2'-Deoxythymidine 3'-monophosphate is the position of the phosphate group. In 2'-Deoxythymidine 5'-monophosphate, the phosphate group is connected to the 5'-carbon atom of the 2'-deoxyribose sugar, while in 2'-Deoxythymidine 3'-monophosphate, the phosphate group is connected to the 3'-carbon atom of the 2'-deoxyribose sugar.

Step-by-step solution

1. Draw the 2'-deoxyribose sugar component

First, draw the pentagonal structure of 2'-deoxyribose sugar, remembering that in deoxyribose, the 2'-carbon lacks an OH group. Instead, it has an H atom. Number the carbon atoms in the sugar ring clockwise, starting with the first carbon connected to the base.

2. Draw the thymine base

Next, draw the nitrogenous base thymine. Thymine is a pyrimidine, consisting of a six-membered ring with two nitrogen atoms (at positions 1 and 3) and two carbonyl groups (at positions 2 and 4). The fifth carbon atom in the ring is linked to a methyl group. Connect this base to the 1'-carbon atom of the 2'-deoxyribose sugar.

3. Draw the phosphate group for (a) 2'-Deoxythymidine 5'-monophosphate.

Now, for the nucleotide (a), draw the phosphate group. This consists of a phosphorus atom double-bonded to an oxygen atom and connected to three other oxygen atoms. One of these oxygen atoms is negatively charged (indicated by a minus sign). Connect this phosphate group to the 5'-carbon atom of the 2'-deoxyribose sugar.

4. Draw the phosphate group for (b) 2'-Deoxythymidine 3'-monophosphate.

Finally, for the nucleotide (b), draw the phosphate group similarly to step 3. However, this time, connect the phosphate group to the 3'-carbon atom of the 2'-deoxyribose sugar. Following these steps, we have drawn the structural formula for each nucleotide: (a) \(2^{\prime}\)-Deoxythymidine \(5^{\prime}\)-monophosphate: Deoxyribose sugar ring connected to thymine at the 1'-carbon and a phosphate group at the 5'-carbon. (b) \(2^{\prime}\)-Deoxythymidine \(3^{\prime}\)-monophosphate: Deoxyribose sugar ring connected to thymine at the 1'-carbon and a phosphate group at the 3'-carbon.