Nucleotides & Nucleic Acids RNA structure Single-stranded (ss) RNAs

Nucleotides & Nucleic Acids RNA structure - rRNA

Nucleotides & Nucleic Acids RNA structure - tRNA, hammerhead ribozyme, Tetrahymena group I intron (catalytic)

Nucleotides & Nucleic Acids Chemistry - denaturation High temp/pH No 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 free nt  single strands  double stranded (can monitor transition from ds to ss)

Nucleotides & Nucleic Acids Chemistry - heat denaturation related to absorption

Nucleotides & Nucleic Acids Chemistry - denaturation Electron microscopy

Nucleotides & Nucleic Acids Sequencing 3’ 2’

Nucleotides & Nucleic Acids Sequencing

Nucleotides & Nucleic Acids Biosynthesis and Degradation Biosynthesis: De novo pathways - uses metabolic precursors (AAs, ribose 5- phosphate, CO 2, NH 3 ) Salvage pathways - recycle free bases and nucleosides released from nucleic acid breakdown

Nucleotides & Nucleic Acids Biosynthesis: De novo pathways

Nucleotides & Nucleic Acids Biosynthesis: 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 blood Caused 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 drugs Cancer cells grow rapidly, so they are in constant need of nucleotides Cancer cells more sensitive than normal cells to inhibitors of nucleotide biosynthesis Analogs of glutamine Used in de novo synthesis

Nucleotides & Nucleic Acids Chemotherapeutic drugs Target enzymes