Chapter 1 (nucleic acid structure) Flashcards
Chemotherapeutics that target S phase
Methotrexate , 5-fluorouracil and hydroxyurea
On what phase does Bleomycin target ?
G2 phase
Chemotherapeutics that target M phase
Vincristine , vinblastine and paclitaxel
Non-cell cycle specific chemotherapeutics ?
Cyclophosphamide and Cisplatin
Reversed transcription is commonly associated with ?
Retroviruses
Base only present in DNA
Thymine
Base only present in RNA
Uracil
Which base is almost always attached to deoxyribose ?
Thymine
Chargaff’e rules
In dsDNA : the amont of A equals that of T and amount of G equals that of C thus total purines equals total pyrimidines
Histones are rich in which proteins ?
Lysine and arganine
Can induce negative supercoiling in E coli DNA ?
DNA gyrase ( DNA topoisomerase ll )
Chromosome abnormalities can be assessed by ?
Karyotype analysis of metaphase chromosomes or Banding techniques of prophase and prometaphase chromosomes
Where and when does transcription occur ?
In the nucleus throughout the interphase ( G1-S-G2 )
Where and when does translation occur ?
In the cytoplasm throughout the cell cycle (G1-S-G2-M)
Where and when does replication occur ?
In the nucleus during S-phase
How the cell cycle is being controlled ?
By Cyclins and Cyclin- dependent kinases
Adenosine deaminase deficiency ?
SCIDS
Purines other than adenine and guanine ?
Xanthine , hypoxanthine and uric acid
Why does nucleoside di and tri phosphate are high energy compounds ?
Because of the hydrolytic energy associated with the acid anhydride bonds
Watson-Crick DNA ?
Right handed double helical molecule with about 10 base pairs per complete turn of the helix
Z-DNA ?
Rare left handed double helical form of DNA that occurs in C-G rich sequences
Daunorubicin and Doxorubicin mechanism ?
Intercalating between the bases of DNA interfering with the activity of Topoisomerase ll and preventing proper replication ( used in ttt of leukemias )
Cisplatin mechanism ?
Bind tightly to the DNA causing structural distortion and malfunction
Methods for double helical DNA denaturation ?
Heat
Alkaline ph
Chemicals : formamide and urea
Where does ribosomal assembly occur ?
In the nucleolus
