Question

Which force type maintains strand integrity along the sugar-phosphate backbone of DNA?

Options

• Base stacking interactions

• Phosphodiester bonds (covalent bonds)

• Hydrogen bonds

• Hydrophobic forces

Answer 1

Phosphodiester bonds are strong covalent bonds that connect the 3′ carbon of one deoxyribose sugar to the 5′ carbon of the next sugar via a phosphate group. These bonds form the sugar-phosphate backbone and are responsible for maintaining strand integrity. Unlike the weak non-covalent hydrogen bonds between bases, phosphodiester bonds cannot be broken during normal replication or transcription processes.