Nucleic acids 1 Flashcards
Nucleotides Nucleosides Conformers DNA structure and forms DNA vs RNA nucleases
mRNA 🡆protein
this process is called?
Translation
DNA 🡆 mRNA is called
Transcription
INHIBITS:
⮞ purine biosynthesis
⮞ xanthine oxidase activity
allopurinol
Cytarabrine is used for _____ therapy
cancer
Azathioprene is used during _______ for supression of immunulogic rejection
organ transplantation
Translation occurs in the _______ located in the cytoplasm
ribosomes
In HIV, the enzyme _____ converts RNA genome to a viral DNA
Reverse transcriptase
_____ units are called nucleotide
monomeric
What are the major components of a nucleotide?
⮞ Phosphate group
⮞ sugar
⮞ nitrogenous base
The ____ group in a nucleotide is the reason why it is negatively charged.
phosphate
Nitrogenous base is linked to the _____ of sugar
Carbon 1’
Phosphate group is linked to the _____ of sugar
Carbon 5’
In what carbon is the difference between a deoxyribose and ribose?
carbon 2’
____ is a more stable conformation than C3’-endo/A-form
C2’-endo/B-form
Purines have 2 rings and 8 atoms. It’s bases are Guanine and Adenine. Are both statements correct?
NO, purines have 9 atoms.
Pyrimidines have 6 atoms and 1 ring only. It’s bases are cytosine, uracil and thymine. Are both statements correct?
YES
Under cellular pH conditions, phosphoric acid loses ______ to give a hydrogen phosphate ion
2 hydrogen atoms
What is the term for the linkage of a phosphate group with a sugar?
phosphoester bond
What are the components of the nucleoside?
base and sugar
What is the term for the linkage of a sugar and a base?
glycosidic bond
between the conformations of nucleosides, which is the most favored for its stability?
anti conformation
Nucleotides have a ______ attached to the C5’ end
free phosphate group
Nucleotide have a _______ attached to the C3’ end
free hydroxyl group
What are the major stacking forces of bases in DNA?
⮞ Hydrophobic interaction
⮞ Van Der Waals Forces
What is the significance of the major groove and the minor groove?
the site where transcription factors interact
According to one of Chargaff’s Rules, the sum of the purine residues equals the
sum of pyrimidine residues
According to Watson-Crick Base pairs,
Adenine - Thymine:
2 hydrogen bonds
Defined by Watson-Crick B-form DNA from 1953,
DNA contained deoxyribonucleosides in _____ linkage
5’-3’ phosphodiester
The A-form is a ________ double helix
Right-handed
Z form DNA is a _______ helical rotation
left-handed
What form of DNA is the most stable?
B form (Watson-Crick structure)
According to Watson-Crick Base pairs,
Cytosine - Guanine:
3 hydrogen bonds
