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Exploring DNA: Structure, Replication, and Genetics

Discover the intricacies of DNA, from its components and replication process to organization in chromosomes. Uncover the roles of key figures like Watson, Crick, Franklin, and more in unraveling DNA's mysteries.

cathleen-guerrero
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Exploring DNA: Structure, Replication, and Genetics

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  1. DNA (deoxyribonucleic acid) I. Watson and Crick II. DNA Structure A. Components of DNA B. Patterns of base pairing III. DNA replication A. Assembly of nucleotide strands B. Replication enzymes IV. Organization of DNA in chromosomes base Watson and Crick nucleotide Linus Pauling Maurice Wilkins Rosalind Franklin

  2. DNA structure II. DNA StructureA. Monomers of DNA

  3. B. Patterns of base pairing Antiparallel base nucleotide

  4. DNA structure

  5. Who, among the following, was not a co-discoverer of the • structure of DNA? • Linus Pauling b. Rosalind Franklin • c. Maurice Wilkins d. Francis Crick To what carbon of deoxyribose does adenine attach? a. 1’ b. 2’ c. 3’ d. 4’ e. 5’ To what carbon of deoxyribose does a new nucleotide attach? a. 1’ b. 2’ c. 3’ d. 4’ e. 5’

  6. The two jobs of DNA Self replication and genetic code

  7. III. DNA replication A. Assembly of nucleotide strandsB. Replication enzymes Repair enzymes After DNA rep, sister chromatids stay attached at centromere Enzymes: DNA polymerases

  8. III. DNA replication

  9. IV. Organization of DNA in chromosomes Histone proteins 3 bases/ amino acid 10,000 bases/ protein (1 gene) 3,000,000,000 base pairs/ genome 22,000 genes/ genome Human Genome Project homologous

  10. How many bases does it take to code for one amino acid? a. 1 b. 2 c. 3 d. 5 Approximately, how many genes in the human genome? a. 10, 000 b. 20, 000 c. 30, 000 d. 60, 000 • What is the role of histone proteins? • They neutralize the negative charges of DNA • They allow DNA to coil up tightly • Both a and b • Neither a or b

  11. DNA sequences in the human genome

  12. DNA fascinating fact

  13. What are the most common elements of our DNA? • Coding sequences • Regulatory sequences • Introns • Transposons • What are transposons? • DNA segments between exons • Random repetitive DNA • DNA coding sequences • DNA segments that make copies of themselves

  14. Protein synthesis I. Protein synthesis A. Transcription - Amanita and RNA polymerase B. Classes of RNA/ RNA versus DNA C. Translation 1. The genetic code 2. Translation, the final steps II. Mutations A. Types of mutations B. Origins of mutations III. Regulation of gene activity IV. Viruses

  15. RNA versus DNA

  16. RNA versus DNA 3 types of RNA

  17. Overview of protein synthesis Transcription: same language Translation: different language pp 191-198

  18. Overview of protein synthesis

  19. No Thymine, instead RNA has Uracil A. Transcription Puff

  20. Introns and exons Exon shuffling SNURPS Collagen gene has 50 introns Osteogenesis imperfecta

  21. Replication versus transcription The ultimate purpose of replication is In replication, DNA unzips In replication, DNA nucleotides are brought in In replication, both sides of the helix are replicated In replication, DNA polymerases do all the work DNA replication takes place in DNA doesn’t leave the nucleus RNA is processed

  22. Amanita and RNA polymerase

  23. Messenger RNA DNA: TAC CAT GAG ACT … ATC mRNA: AUG GUA CUC UGA … UAG

  24. Ribosomal RNA and ribosomes

  25. Ribosomal RNA and ribosomes

  26. Transfer RNA

  27. Codons and anticodons DNA: TAC CAT GAG ACT … ATC mRNA: AUG GUA CUC UGA … UAG tRNA: UAC CAU GAG ACU … AUC

  28. C. Translation 1. The genetic code2. Translation, the final steps Codons wobble

  29. Which RNA carries amino acids from a pool to the ribosome for assembly? a. tRNA b. rRNA c. mRNA d. vRNA How many coding codons are there? a. 20 b. 30 c. 61 d. 64 • Which of the following is not a difference between RNA and • DNA? • The sugar is different • The nucleotides are different • The helix structure is different • The bond between phosphate and sugar is different

  30. 2. Translation, the final steps

  31. 2. Translation, the final steps

  32. II. Mutations Mutation = change in nucleotide sequence Mutations can be: bad Selected against neutral Drift good Selected for Three examples of gene mutations 1. Point mutation 2. Frameshift mutation 3. Gene duplication Most mutations are caused by errors in DNA replication Mutagens Mutations in coding and non-coding regions Mutations in somatic and germ cells

  33. Point mutations ACT GAG TCA TGA TTC AGG Example: Sickle cell trait A and B blood types

  34. Frameshift mutations (type of point mutation) Insertion ACT GAG CAT TGA A CT CGT A.. … … Deletion O type blood ACT GAG CAT _ TGA TCG TA. … ..

  35. Gene duplication Causes 1. Uneven crossing over 2. Replication slippage

  36. Gene duplication 3N Entire genome duplicated

  37. B. Origins of mutations mutagens viruses Environmental insults Errors in DNA replication

  38. RNA DNA Small Pox III. Viruses A. Diversity 1. DNA viruses 2. RNA viruses Retroviruses: Reverse transcription Cold Ebola Reverse transcriptase Flu HIV

  39. B. Viruses structure and function protein coat viral DNA or RNA Infect more cells Living or non-living?

  40. C. HIV 1. Pandemic

  41. C. HIV 2. structure • 2 strands of RNA • 9 genes • 3 enzymes • Protein coat • Lipid membrane • HIV target cell? • Macrophages • Helper T cells

  42. 2. infection cycle HIV evolution and reverse transcriptase HIV resistance in humans HIV target? CCR5

  43. HIV replication

  44. infection and budding

  45. origin polio virus HIV SIV

  46. The end

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