Problem 107 - Chemistry An Atoms First Approach

Question

Which base will hydrogen-bond with uracil within an RNA molecule? Draw the structure of this base pair.

Step-by-Step Solution

Answer

The base that hydrogen-bonds with uracil (U) within an RNA molecule is adenine (A). The base pair can be represented as: NH2 O | || N N - ** / \ / \ C - C C C - O | || N - C - HN \\ N - C | | N -- H | | H N H N \ H

Step 1: Identify the base pairs

Within an RNA molecule, certain bases preferentially pair with each other to form hydrogen bonds. Adenine (A) pairs with uracil (U) and guanine (G) pairs with cytosine (C). Therefore, the base that can hydrogen-bond with uracil (U) is adenine (A).

Step 2: Draw the structure of uracil

The structure of uracil can be represented as follows: O || N / \ HN - C - C - O \\ / N \ H

Step 3: Draw the structure of adenine

The structure of adenine can be represented as follows: NH2 | N / \ C - C - O | || N - C | | H N \ H

Step 4: Draw the base pair of adenine and uracil

The hydrogen bond between adenine (A) and uracil (U) can be represented as follows: **Adenine (A)** NH2 | N / \ C - C O | || || N - C <---> N - ** | | / \ H N --H C C - O | \\ H N -- H **Uracil (U)** In the above structure, the dashed lines (\<--->) indicate the hydrogen bonds formed between the bases adenine and uracil.