AP BIOLOGY

Detailed explanation-1: -Complementary bases attach to one another (A-T and C-G). The primary enzyme involved in this is DNA polymerase which joins nucleotides to synthesize the new complementary strand. DNA polymerase also proofreads each new DNA strand to make sure that there are no errors.

Detailed explanation-2: -One of the key molecules in DNA replication is the enzyme DNA polymerase. DNA polymerases are responsible for synthesizing DNA: they add nucleotides one by one to the growing DNA chain, incorporating only those that are complementary to the template.

Detailed explanation-3: -DNA polymerase cannot synthesize new DNA without a pre-existing 3′-OH. Thus, DNA replication requires an RNA primer to initiate strand formation.

Detailed explanation-4: -As the new nucleotides line up opposite each parent strand by hydrogen bonding, enzymes called DNA polymerases join the nucleotides by way of phosphodiester bonds.

Detailed explanation-5: -DNA polymerase enzymes cannot begin a new polynucleotide chain by linking two nucleoside triphosphates together. Instead, they absolutely require a base-paired 3′-OH end of a primer strand on which to add further nucleotides (see Figure 5-4).