Question

The number of phosphodiester bonds and hydrogen bonds broken due to action of EcoRI at one recognition sequence?

• A. $4\&16$
• B. $2\&4$
• C. $2\&8$
• D. $6\&8$

Answer 1

The correct option is C $2\&8$

The recognition site for EcoRI is 5’-GAATTC-3’ and the action of the enzyme nicks 2 phosphodiester bonds between G and A in the backbone of the two strands of DNA. Along with the phosphodiester bonds, a total of eight hydrogen bonds are broken in between the two strands, i.e. the bonds between A and T connecting the two strands.