Flashcards in 1. Nucleic Acid Structure and Organization Deck (37):
DNA replication is..
The process in which each chromosome is duplicated before cell division
Where and when does transcription occur?
In the nucleus, throughout interphase
Where and when does translation of RNA occur?
In the cytoplasm, throughout the cell cycle
When and where does DNA replication occur?
In the nucleus, during S phase
What is M phase?
Mitosis, cell divides to form two daughter cells
What is interphase?
Time between two cell divisions/mitoses
When are genes expressed?
Phases of interphase are..
G1, S and G2
G1 phase is..
Period of cellular growth preceding DNA synthesis
G0 phase is..
Cells that have stopped cycling
S phase is..
DNA replication, leading to two identical chromatids
G2 phase is..
Period of cellular growth after DNA replication but preceding mitosis. Checked for errors.
Methotrexate, r-fluorouracil, hydroxyurea
Paclitaxel, vincristine, vinblastine
Non cell-cycle specific chemotherapeutics
Cyclins and cyclin-dependent kinases
Nitrogenous base, five-carbon sugar (pentose) and phosphate
Contain two rings. Adenine, guanine. (others: xanthine, hypoxanthine, uric acid)
Contain one ring. Cytosine, uracil, thymine
Base added to number 1 carbon of sugar
Nuclease + phosphate(s) to 5' carbon
Difference ribose and deoxyribose
Ribose has OH group at 2' carbon of the sugar, deoxyribose has H.
Nomenclature Base, Nucleoside, Nucleotide
Linked by 3',5' phosphodiester bonds
Have distinct 3' and 5' ends, thus polarity
Sequence always specified as 5'->3'
%A = %T, %G = %C
% purines = % pyrimidines
Mostly Watson-Crick DNA or B-DNA, right handed, 10 bps per complete turn of helix.
Left-handed rare in G-C rich sequences, Z-DNA.
Daunorubicin and doxorubicin
Exert their effects by intercalating between bases of DNA, interfering with topoisomerase II and preventing proper replication of DNA.
Binds tightly to DNA, causing structural distortion and malfunction
Disrupt hydrogen bonding and base stacking
Heat, alkaline pH, chemicals (form amide, urea)
Negative: more loosely wound (biological reactions)
Positive: more tightly
-> Topoisomerase, makes transient breaks
Histones are rich in
Lysine and arginine (positive charge)
Two copies of each H2A, H2B, H3 and H4 aggregate
DNA winds around outside of histone octamer
AKA beads on a string, 10nm chromatin fiber
H1 associates with nucleosome, 30nm fiber
Karyotype analysis uses..
Metaphase chromosomes, highly condensed