Structure of dna and replication2012
- 2. DNA: Genetic control of protein structure and function
- 3. James Watson (L) and Francis Crick (R), and the model they built of the structure of DNA
- 4. Overview of DNA Structure
- 5. The structure of DNA and RNA Genetic material of living organisms is either DNA or RNA. DNA – Deoxyribonucleic acid RNA – Ribonucleic acid Genes are lengths of DNA that code for particular proteins.
- 6. DNA and RNA are polynucleotides Both DNA and RNA are polynucleotides. They are made up of smaller molecules called nucleotides. Nucleotide DNA is made of two polynucleotide strands: Nucleotide Nucleotide Nucleotide Nucleotide Nucleotide Nucleotide Nucleotide Nucleotide Nucleotide Nucleotide RNA is made of a single polynucleotide strand: Nucleotide Nucleotide Nucleotide Nucleotide Nucleotide
- 7. Structure of a nucleotide A nucleotide is made of 3 components: A Pentose sugar This is a 5 carbon sugar The sugar in DNA is deoxyribose. The sugar in RNA is ribose.
- 8. Structure of a nucleotide A Phosphate group Phosphate groups are important because they link the sugar on one nucleotide onto the phosphate of the next nucleotide to make a polynucleotide.
- 9. Structure of a nucleotide A Nitrogenous base In DNA the four bases are: – Thymine – Adenine – Cytosine – Guanine In RNA the four bases are: – Uracil – Adenine – Cytosine – Guanine
- 10. Nitrogenous bases – Two types Pyrimidines Purines Thymine - T Adenine -A Cytosine - C Guanine -G Uracil - U
- 11. Adenine
- 12. Guanine
- 14. The Structure of DNA and RNA
- 15. Sugar phosphate bonds (backbone of DNA) Nucleotides are connected to each other via the phosphate on one nucleotide and the sugar on the next nucleotide A Polynucleotide
- 16. Ladder Configuration and DNA Replication
- 17. Base pairing The Nitrogenous Bases pair up with other bases. For example the bases of one strand of DNA base pair with the bases on the opposite strand of the DNA.
- 19. The Rule: Adenine always base pairs with Thymine (or Uracil if RNA) Cytosine always base pairs with Guanine. Basesare held together by weak hydrogen bonds (bonds between hydrogen and F, N, or O)
- 20. Complementary base pairing Purines Pyrimidines Adenine Thymine Adenine Uracil Guanine Cytosine THE DNA Sequence Game - Wanna Play?
- 21. The Replication of DNA- THE S PHASE
- 24. The 5’ to 3’ – 3’ to 5’ Rule As far a 5-3 and 3 to 5: – If one strand goes from 5’ to 3’, the other goes from 3’ to 5’ 5’- ATGCAACTCGAC – 3’ 3’- TACGTTGAGCTG – 5’ Always observe the Base Pair Rule!
- 25. Replication DNA Replication – Ann’y
- 26. Overview of DNA Replication
- 27. DNA REPLICATION OVERVIEW Involves 20 different enzymes and other proteins. IN THREE MAJOR STEPS: (S PHASE) 1. Enzymes attach to existing DNA – Break Hydrogen Bonds between base pairs – Double Helix unwinds(TEMPLATE for new bases) – Enzyme - Helicase 2. NEW AND MATCHING strand is SYNTHESIZED for each existing strand. DNA POLYMERASE – enzymes that carries out replication of strand. Work in ONE direction Work from opposite ends of strands. 3. New strands are sealed by - LIGASE
- 28. Simplified illustration of replication The two strands of DNA separate from one another Each strand serves as a template (model) for a new strand Each new DNA molecule consists of one old strand and one new strand
- 33. Replication Forks Areas where DNA double strands have been “unzipped” for replication to occur.