DNA Structure and Replication — Flashcards

Flashcard 1: DNA & RNA are made of _____ connected via a phosphodiester bond

Answer: nucleotide monophosphates

Flashcard 2: Leading strand synthesis is carried out by DNA polymerase _____.

Answer: DNA polymerase ε (epsilon)

Extra: In eukaryotes: - **DNA polymerase ε (epsilon)**: Leading strand synthesis. - **DNA polymerase δ (delta)**: Lagging strand synthesis. In prokaryotes (e.g., *E. coli*), **DNA polymerase III** is responsible for both leading and lagging strand synthesis.

Flashcard 3: Which DNA polymerases are primarily responsible for DNA repair in prokaryotes and eukaryotes?

Answer: Prokaryotes: **DNA polymerase I** Eukaryotes: **DNA polymerase β**

Extra: In prokaryotes, DNA polymerase I is involved in DNA repair and primer removal (due to its 5'→3' exonuclease activity). In eukaryotes, DNA polymerase β is the primary polymerase involved in DNA repair (specifically base excision repair).

Flashcard 4: The enzymes that repair mismatched base mutations (eg. spontaneous/toxic deaminations) are _____ and DNA ligase

Answer: DNA polymerase

Flashcard 5: The enzyme which adds _____ to 3' ends of chromosomes to avoid loss of genetic material with every duplication is known as Telomerase

Answer: TTAGGG

Flashcard 6: H2A, H2B, H3 and H4 are called _____ histones.

Answer: core

Flashcard 7: Unwinding /Denaturation of DNA is started by _____

Answer: Ori-binding protein.

Flashcard 8: _____ DNA is generated by the hydrogen bonding of a third strand into a major groove of B-DNA.

Answer: Triple strand

Flashcard 9: In all cells, replication can occur only from a _____-stranded DNA template

Answer: single (double/single)

Flashcard 10: Guanosine is converted to _____ via the enzyme purine nucleoside phosphorylase (purine salvage)

Answer: guanine