Question

A biochemist is analyzing an aqueous solution of a pure unidentified macromolecule that she isolated from the cytosolic fraction of plant cells. She determined that the macromolecule is probably DNA from chloroplasts and mitochondria by adding an enzyme that catalyzed the destruction of the macromolecule. The enzyme most likely broke which type of bonds?

a.glycosidic
b.peptide
c.phosphodiestes
d.None of the above

Answer 1

Answer: Option C) phosphodiesters

Explanation:

Since DNA, also known as deoxyribonucleic acid, is a macromolecule consisting of several repeating deoxynucleotides units of nitrogenous bases (Adenine, thymine, cytosine and guanine), where each is linked at the 3' position of its pentose sugar to the phosphate group attached to the 5' position of the pentose sugar on the adjacent nucleotide by a phosphodiester bond; the enzyme most likely broke the 3',5'-phosphodiester bonds, therefore leading to the unwinding of its double strands.