Nucleic Acid Biochemistry — Flashcards

Flashcard 51: A _____ is negatively charged DNA wrapped around the outside of positively charged proteins called histones

Answer: nucleosome (10 nm chromatin)

Flashcard 52: In response to DNA damage, p53 initially attempts to _____ the cell cycle and facilitates the activity of DNA repair enzymes. Bonus: What does p53 induce that inhibits the cell cycle?

Answer: halt

Flashcard 53: Recognition and facilitation of excision of _____ occur via enzymes found on two genes: MSH2 (MutS) or MLH1 (MutL)

Answer: mismatched nucleotides

Flashcard 54: _____ is found in telomeres with parallel four-stranded DNA and has high guanine content.

Answer: G-quartet DNA

Flashcard 55: RNA polymerase _____ makes rRNA

Answer: I

Flashcard 56: 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 57: _____ polymerase requires an RNA primer to initiate synthesis, which is complementary and antiparallel to the DNA template.

Answer: DNA

Extra: DNA polymerase requires a free 3'-OH group to begin adding nucleotides; this is provided by an RNA primer synthesized by primase (an RNA polymerase).

Flashcard 58: Glutamine-PRPP amidotransferase (purine synthesis) is regulated by negative feedback via _____, IMP, and GMP

Answer: AMP

Flashcard 59: UDP is converted to _____ via the enzyme ribonucleotide reductase (pyrimidine synthesis)

Answer: dUDP

Flashcard 60: In _____, cuts are made several nucleotides away on either side of the damaged base.

Answer: nucleotide excision (mechanism of DNA repair)