Nucleotides & Nucleic Acids

RNA structure

Single-stranded (ss) RNAs

Nucleotides & Nucleic Acids

RNA structure - rRNA

Nucleotides & Nucleic Acids

RNA structure - tRNA

Nucleotides & Nucleic Acids

Chemistry - denaturation

_______________No covalent bonds broken

__________________

SLOW

QUICK

____________________

Nucleotides & Nucleic Acids

Chemistry - denaturation

High temp/pHNo covalent bonds broken

Normal temp/neutral pH

SLOW

QUICK

Normal temp/neutral pH

Nucleotides & Nucleic Acids

Chemistry - denaturation

Lowest absorption of UV light

Lower absorption of UV light than free nucleotides

HYPOCHROMIC EFFECT -decrease in absorption as you go from

(can monitor transition from ds to ss)

Nucleotides & Nucleic Acids

Chemistry - denaturation

Lowest absorption of UV light

Lower absorption of UV light than free nucleotides

HYPOCHROMIC EFFECT -free nt (highest UV absorption) ssDNA dsDNA (lowest UV absorption)(can monitor transition from ds to ss)

Nucleotides & Nucleic Acids

Chemistry - heat denaturationre

late

d to

abs

orpt

ion

Nucleotides & Nucleic Acids

Chemistry - 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 - ____________________________ released from 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 released from nucleic acid breakdown

Nucleotides & Nucleic AcidsBiosynthesis:De novo pathways

Nucleotides & Nucleic AcidsBiosynthesis:De novo pathways - regulation

Nucleotides & Nucleic Acids

Degradation:

Allopurinol

Nucleotides & Nucleic Acids

Degradation:

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] causes general deficiency of other dNTPS in lymphocytes

Poor development of T and B lymphocytes, ineffective immune system

Leads to severe combined immunodeficiency syndrome (SCIDS), also called “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 xanthine oxidase (enzyme that catalyzes step that makes uric acid)

Nucleotides & Nucleic Acids

Chemotherapeutic drugsCancer cells grow rapidly, so they are in constant need of nucleotidesCancer cells more sensitive than normal cells to inhibitors of nucleotide biosynthesis

Analogs of glutamine

Used in de novo synthesis

Nucleotides & Nucleic Acids

Chemotherapeutic drugsTarget enzymes