Post on 09-Jun-2020
transcript
Nucleotides & Nucleic AcidsRNA structure
Single-stranded (ss) RNAs
Nucleotides & Nucleic AcidsRNA structure - rRNA
Nucleotides & Nucleic AcidsRNA structure - tRNA
Nucleotides & Nucleic AcidsChemistry - denaturation
_______________No covalent bonds broken
__________________
SLOW
QUICK
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Nucleotides & Nucleic AcidsChemistry - denaturation
High temp/pHNo covalent bonds broken
Normal temp/neutral pH
SLOW
QUICK
Normal temp/neutral pH
Nucleotides & Nucleic AcidsChemistry - denaturation
Lowest absorption of UV light
Lower absorption of UV lightthan free nucleotides
HYPOCHROMIC EFFECT -decrease in absorption as you go from → →
(can monitor transition from ds to ss)
Nucleotides & Nucleic AcidsChemistry - denaturation
Lowest absorption of UV light
Lower absorption of UV lightthan free nucleotides
HYPOCHROMIC EFFECT -free nt (highest UV absorption)→ ssDNA → dsDNA (lowest UV absorption)(can monitor transition from ds to ss)
Nucleotides & Nucleic AcidsChemistry - heat denaturation
rela
ted
to a
bsor
ptio
n
Nucleotides & Nucleic AcidsChemistry - denaturationElectron microscopy
Nucleotides & Nucleic AcidsSequencing
3’ 2’
Nucleotides & Nucleic AcidsSequencing
Nucleotides & Nucleic AcidsBiosynthesis and Degradation
Biosynthesis:De novo pathways - uses ________________________________(AAs, ribose 5-phosphate, CO2, NH3)
Salvage pathways - ____________________________ releasedfrom nucleic acid breakdown
Nucleotides & Nucleic AcidsBiosynthesis and Degradation
Biosynthesis:De novo pathways - uses metabolic precursors (AAs, ribose 5-phosphate, CO2, NH3)
Salvage pathways - recycle free bases and nucleosides releasedfrom nucleic acid breakdown
Nucleotides & Nucleic AcidsBiosynthesis:De novo pathways
Nucleotides & Nucleic AcidsBiosynthesis:De novo pathways - regulation
Nucleotides & Nucleic AcidsDegradation:
Allopurinol
Nucleotides & Nucleic AcidsDegradation:
Deficiency in adenosine deaminase (causes ADA deficiency)Cannot break down adenosine, so it builds up, also [dATP] builds up
dATP is an inhibitor of ribonucleotide reductase, high [dATP] causesgeneral deficiency of other dNTPS in lymphocytes
Poor development of T and B lymphocytes, ineffective immune system
Leads to severe combined immunodeficiency syndrome (SCIDS), alsocalled “bubble boy” disease
First gene therapy for ADA
Elevated uric acid in bloodCaused by deficiency of one of purine metabolic enzymes
Causes gout
Uric acid causes inflammation of joints, problems in kidneys
Treatment = Drug allopurinol, which is an inhibitor of xanthineoxidase (enzyme that catalyzes step that makes uric acid)
Nucleotides & Nucleic AcidsChemotherapeutic drugsCancer cells grow rapidly, so they are in constant need of nucleotidesCancer cells more sensitive than normal cells to inhibitors of nucleotidebiosynthesis
Analogs of glutamine
Used in de novo synthesis
Nucleotides & Nucleic AcidsChemotherapeutic drugsTarget enzymes