Question

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

Short answer

Adenine (A) forms a base pair with Uracil (U) within an RNA molecule through two hydrogen bonds. The hydrogen bond occurs between the Nitrogen atom at position 1 in Adenine and the Oxygen atom at position 4 in Uracil, as well as between the Nitrogen atom at position 6 in Adenine and the Nitrogen atom at position 3 in Uracil. A visual representation of the Adenine-Uracil base pair is recommended to better understand their molecular structure and hydrogen bonding.

Step-by-step solution

Identifying possible base pairs with Uracil

As mentioned before, the RNA bases are adenine, guanine, cytosine, and uracil. These bases pair in specific ways due to their molecular structures. Uracil forms base pairs with Adenine in RNA molecules due to their ability to form hydrogen bonds with each other.

Understanding Hydrogen Bonds

A hydrogen bond is a type of attractive intermolecular force that exists between two partial electric charges of opposite polarity. Although stronger than most other intermolecular forces, the hydrogen bond is much weaker than both covalent and ionic bonds. This type of bond occurs specifically between hydrogen atom bonded to a strongly electronegative atom and another different electronegative atom that has a lone pair of electrons.

Explaining Adenine-Uracil base pair

Adenine (A) forms a base pair with Uracil (U) via two hydrogen bonds, thus linking the opposite strands of the RNA molecule in a double helix. In these base pairs, adenine always pairs with uracil.

Drawing the Adenine-Uracil base pair

Drawing chemical structures might be challenging based on the medium used to explain this. However, remember that Adenine has six-member ring attached to a five-member ring, with Nitrogen atoms at positions 1,3,7 and 9. Nitrogen atom at position 1 forms hydrogen bond with Uracil's Oxygen atom at position 4. The Nitrogen at position 6 in Adenine forms hydrogen bond with Uracil's Nitrogen at position 3. Special attention must be paid in demonstrating the hydrogen bonds between the bases. Although not possible within this text, a visual representation of the Adenine-Uracil base pair is recommended for better understanding.