Why are hydrogen bonds essential to the structure of DNA?

• A. They stabilize the double helix by holding complementary base pairs together.
• B. They form the covalent backbone of each DNA strand.
• C. They provide the energy required for DNA replication.
• D. They link nucleotides together through phosphodiester bonds.

Answer: (A)

Verified step by step guidance

1. Understand the structure of DNA: DNA is composed of two strands forming a double helix. Each strand consists of a sugar-phosphate backbone and nitrogenous bases (adenine, thymine, cytosine, and guanine) that pair with complementary bases on the opposite strand.
2. Learn about complementary base pairing: Adenine (A) pairs with thymine (T) through two hydrogen bonds, and cytosine (C) pairs with guanine (G) through three hydrogen bonds. These bonds are essential for the stability of the DNA structure.
3. Recognize the role of hydrogen bonds: Hydrogen bonds are weak interactions that stabilize the double helix by holding the complementary base pairs together. They allow the strands to separate during processes like replication and transcription without requiring excessive energy.
4. Differentiate hydrogen bonds from other bonds: Hydrogen bonds are not involved in forming the covalent backbone of DNA (which consists of phosphodiester bonds) or linking nucleotides together. They specifically stabilize the base pairing within the double helix.
5. Conclude the importance of hydrogen bonds: Hydrogen bonds are crucial for maintaining the integrity of the DNA structure, ensuring accurate base pairing, and facilitating biological processes like replication and transcription.