Final answer:
In DNA, hydrogen bonds connect the nitrogenous bases while phosphodiester bonds link the nucleotide backbone. DNA denaturation can be achieved by heating, separating the strands, and reannealing through cooling, allowing hydrogen bonds to reform. However, RNA, which typically does not form double-stranded structures like DNA, may not reanneal if mixed with DNA.
Step-by-step explanation:
The two bonds made in DNA are hydrogen bonds and phosphodiester bonds. Hydrogen bonds are between the nitrogenous base pairs of the double helix and are weaker compared to phosphodiester bonds, which connect the sugar and phosphate groups of the nucleotide backbone. Hydrogen bonds play a role in holding the two strands of DNA together and allow for the specific pairing of bases (adenine with thymine, and guanine with cytosine), essential for reannealing during DNA replication and repair. The phosphodiester bonds provide structural integrity to a strand of DNA by connecting its nucleotide subunits.
Denaturing nucleic acids into single strands involves heating the DNA, which breaks the hydrogen bonds holding the two strands together. Conversely, reannealing involves cooling the denatured single strands, allowing hydrogen bonds to reform between complementary bases. For reannealing to occur, both strands must be present and have complementary sequences. If RNA is added instead of DNA, reannealing may not occur as RNA typically exists as a single strand, and its uracil base does not pair with DNA's thymine.