Final answer:
Phosphodiester bonds are covalent and thus significantly stronger than hydrogen bonds, which are intermolecular attractions and comparatively weaker. Covalent bonds form the sugar-phosphate backbone of DNA, while hydrogen bonds help maintain the double-helix structure.
Step-by-step explanation:
In answering the question of whether phosphodiester bonds or hydrogen bonds are stronger, we can refer to their fundamental chemistry. Phosphodiester bonds are covalent bonds that form between nucleotides in the nucleic acid chain. They result from a dehydration synthesis reaction where water is produced, as phosphates connect the 3' carbon of one nucleotide with the 5' carbon of another
On the other hand, hydrogen bonds are intermolecular attractive forces that occur between molecules, such as the two strands of a DNA double helix. Although hydrogen bonds are essential for the structure and function of biomolecules, they are much weaker than covalent bonds, at approximately 5 to 10% of their strength.
Therefore, phosphodiester bonds are indeed stronger than hydrogen bonds. This is reflected in their bond strength values, which show that hydrogen bonds have a bond strength of about 23 kJ mol-¹, while a typical covalent bond like the O-H bond has a strength of 492 kJ mol-¹.