Chapter 3 and 24: Nucleic struc and org Flashcards
Base Tautomeric forms structures
GO OVER S. 2
Nucleosides makeup (specific with what type of bond)
Nitrogenous base + Sugar
-D-ribose or deoxy-D-ribose sugar that is connected to a base by a beta-N-glycosidic bond
Nucleotides
Nucleoside + Phosphate
-nucleoside in which a molecule of phosphoric acid is esterified with an -OH of the monosaccharide, at the 3’ or 5’ OH
*5’ OH is the default
3’-5’-Cyclic adenosine monophosphate (cyclic adenosine monophosphate, cAMP) derivation and how it is used?
-derived from ATP
-cAMP used in intracellular signal transduction as a secondary messenger
DNA struc. and bases
-deoxyribose
-A,G,C,T
-ex: deoxy= deoxyadenosine–> dAMP–>dADP–>dATP
RNA struc and bases
-ribose
-A,G,C,U (sometimes T)
-ex: Adenine–>Adenosine–>AMP–>ADP–>ATP
Modular struc config struc
know slide 4
Zidovudine
-used in medicine:
nucleoside analog reverse transcriptase inhibitor (NRTI) used to treat HIV
minor bases (RNA vs. DNA and their role)
-RNA (tRNA) contains minor bases
-In DNA minor bases are methylated forms of the major bases
*have roles in regulation or in protecting genetic information
Inosine
-type of Xanthines that is a minor base
-found in tRNAs
-essential for wobble base pairs (anticodon)
DNA and RNA simple def
-known as polynucleotides= nucleotides joined by phosphodiester linkages
-RNA= ribonucleic acids
-DNA=deoxyribonucleic acid
Primary structure seq of DNA
read from the 5’ to 3’ end
what is RNA susceptible to?
Base catalyzed hydrolysis bc it has a 2’ OH
-why DNA is more stable
Erwin Chargaff
found chargaff’s rule
-A=T
-G=C (stronger)
Watson and Crick
solved secondary structure of DNA by using Franklin’s data
-found the double helix
-Crick: crystallographer who knew it was a helix
-used chargaff rule
Rosalind Franklin
-got the X-ray fiber diffraction data
*helped watson and crick with solving DNA struc
Central Dogma
- Replication using DNA polymerase
- Transcription (DNA->RNA) using RNA polymerase
- Translation (RNA->Protein) using ribosomes
- Protein
DNA structure total (facts)
-right/left handed helix
-bases are perpendicular to helix
-bases: minor and major grooves
-phosphate backbones are on the outside
-anti-parallel chains
-bases pairs per helical turn: 10
-Pitch= 34A
-Helix rise per base pair = 3.4A
-Diameter: 20A
-glycosidic bond formation: anti
Nucleotide sugar conformations in DNA/RNA
Syn-adenosine
anti-Adenosine
*sugar is anti to the base
Differentiate between A-DNA, B-DNA, and Z-DNA
A-DNA
-right handed helix
-Major groove: narrow and deep
-Minor groove: wide and shallow
B-DNA
-right handed helix
-Major groove: wide and deep
-minor groove: narrow and deep
Z-DNA
-left handed helix
-Major groove: flat
-minor groove: narrow and deep
RNA-RNA/RNA-DNA hybrids assume which sturcture
A DNA
Z-DNA occurs in what and is favored when?
-occurs in alternating purine-pyrimadine tracts
-favored in high salt concentrations
Telomeres
the ends of linear chromosomes
Tetraplex or Quadruplex DNA have what kind of roles?
roles in transcription, telomere maintenance, DNA recombination etc….
