Nucleotides & Nucleic Acids

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

2. Nucleotides & Nucleic Acids RNA structure - rRNA

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

4. Nucleotides & Nucleic Acids Chemistry - denaturation High temp/pH No covalent bonds broken Normal temp/neutral pH QUICK SLOW Normal temp/neutral pH

5. Nucleotides & Nucleic Acids Chemistry - denaturation Lowest absorption of UV light HYPOCHROMIC EFFECT - decrease in absorption as you go from free nt  single strands  double stranded (can monitor transition from ds to ss) Lower absorption of UV light than free nucleotides

6. Nucleotides & Nucleic Acids Chemistry - heat denaturation related to absorption

7. Nucleotides & Nucleic Acids Chemistry - denaturation Electron microscopy

8. Nucleotides & Nucleic Acids Sequencing 3’ 2’

9. Nucleotides & Nucleic Acids Sequencing

10. Nucleotides & Nucleic Acids Biosynthesis 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

11. Nucleotides & Nucleic Acids Biosynthesis: De novo pathways

12. Nucleotides & Nucleic Acids Biosynthesis: De novo pathways - regulation

13. Nucleotides & Nucleic Acids Degradation: Allopurinol

14. 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)

15. 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

16. Nucleotides & Nucleic Acids Chemotherapeutic drugs Target enzymes