Nucleic Acid Structure And Organization

Question 1

Chemotherapeutic agents functions by targeting specific phases: S-phases (DNA synthesis), G2 (gap 2), M (mitosis), Non cell-cycle specific,
Name them

Answer 1

S: methotrexate, 5-flurouracil, hydroxyurea
G2: bleomycin
M: paclitaxel, vincristine, vinblastine
Non cell-cycle specific: cyclophosphamide, cisplatin

Question 2

Chargaff’s rules

Answer 2

In dsDNA or dsRNA
%A=%T (%U)
%G=%C
%purines=%pyrimidines

Question 3

Polymerases and Nucleases

Answer 3

Polymerases are enzymes that synthesize nucleic acids by forming phosphodiester (PDE) bonds.
Nucleases are enzymes that hydrolyze PDE bonds.
- Exonucleasis remove nucleotides from either the 5’ or 3’ end of a nucleic acid
- Endonucleases cut within the nucleic acid and release nucleic acid fragments