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DNA

DNA. Replication and Protein Synthesis. Central Dogma of Gene Expression. DNA. Deoxyribonucleic Acid Controls cells activities Contains organism’s traits Contains messages to produce proteins. DNA. Monomer- Nucleic Acid. DNA. DNA – 4 bases. Purines Pyrimidines.

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DNA

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  1. DNA Replication and Protein Synthesis

  2. Central Dogma of Gene Expression

  3. DNA • Deoxyribonucleic Acid • Controls cells activities • Contains organism’s traits • Contains messages to produce proteins

  4. DNA • Monomer- Nucleic Acid

  5. DNA

  6. DNA – 4 bases PurinesPyrimidines Adenine bonds with Thymine Guanine bonds with Cytosine

  7. DNA- Base Pairs • Just remember: AT Central Gwinnett A bonds with T C bonds with G

  8. DNA structure • James Watson and Francis Crick 1953 Shaped like a ladder Sides- alternating sugars and phosphates Steps-base pairs joined by hydrogen bonds

  9. DNA Structure • Then ladder is twisted forming a double helix

  10. DNA Replication • During mitosis- chromosomes (DNA) are copied (replicated) • Every cell gets a complete set of chromosomes • Replication- process in which DNA is copied

  11. DNA Replication • Steps to DNA replication • 1. Chemical bonds split between base pairs, DNA is unzipped • 2. Free nucleotide bases pair up with complementary base on DNA strands. Each original strand is called a template. • 3. Sugars and phosphates bond between free nucleotides • 4. Result is 2 identical molecules of DNA. Each new molecule consists of one old strand and one new strand

  12. DNA Replication

  13. DNA Replication Note: Each new DNA molecule is made of one old strand and one new strand

  14. DNA Replication Links • http://www.lewport.wnyric.org/jwanamaker/animations/DNA%20Replication.html

  15. DNA and RNA

  16. DNA and RNA

  17. Types of RNA • mRNA- messenger RNA- single strand copied from one side of the DNA molecule in the nucleus. Moves to the cytoplasm. “Carries the message” • tRNA- transfer RNA- carries the amino acids to make a protein. Carries them to the ribosome and mRNA. • rRNA- ribosomal RNA- bonds with mRNA, site where tRNA brings amino acids to form a protein

  18. Types of RNA mRNA tRNA rRNA

  19. Protein SynthesisTranscription and Translation • Transcription- one side of a DNA molecule is copied forming a mRNA molecule • Translation- protein is formed by joining Amino Acids -sequence of mRNA bases is converted into an amino acid sequence

  20. Protein SynthesisTranscription • 1. DNA unzips • 2. Free floating nucleotides bond to one side of DNA (Uracil bonds with Adenine) • 3. Bases are joined together • 4. mRNA leaves the nucleus and enters the cytoplasm

  21. Protein SynthesisTranslation • Codon- set of three bases, each one codes for one amino acid

  22. Protein SynthesisTranslation Determine the chain of Amino Acids for the following codons AUG CAG UAU GAU GUU UUA CCU UAG Methionine Glutamine Tyrosine Aspartate Valine Leucine Proline Stop

  23. Protein SynthesisSteps of Translation • 1. Ribosome attaches to mRNA • 2. tRNA with anti-codon that is the complement of the codon attaches to mRNA carrying a specific amino acid • 3. Ribosome slides to second codon • 4. Second tRNA with complementary anti-codon bonds with second codon • 5. Amino acid from 1st tRNA bonds with amino acid attached to 2nd tRNA • 6. Ribosome continues down mRNA creating a chain of amino acids until a stop codon is reached

  24. Protein SynthesisSteps of Translation

  25. Protein Synthesis links • http://www.lewport.wnyric.org/jwanamaker/animations/Protein%20Synthesis.html • http://www.wisc-online.com/objects/index_tj.asp?objid=AP1302

  26. A A T T C G A C T A T G T C G T A A template Strand U C G A U A A U C mRNA

  27. A A T T C G A C T A T G T C G T A A template Strand U C G A U A A U C Nucleus mRNA Cytoplasm Ribosome

  28. A A T T C G A C T A T G T C G T A A Template Strand U C G A U A A U C mRNA U C G A U A A U C Nucleus Cytoplasm

  29. A A T T C G A C T A T G T C G T A A Template Strand AA1 AGC U C G A U A A U C tRNA’s Nucleus Cytoplasm

  30. A A T T C G A C T A T G T C G T A A template Strand AA1 tRNA’s AGC U C G A U A A U C Nucleus Cytoplasm

  31. A A T T C G A C T A T G T C G T A A template Strand AA1 • AA2 AGC AAG U C G A U A A U C Nucleus ATP Cytoplasm tRNA’s

  32. A A T T C G A C T A T G T C G T A A Template Strand AGC AA3 AA1 AA1 U U U U C G A U A A U C Nucleus ATP • AA2 Cytoplasm AAG

  33. A A T T C G A C T A T G T C G T A A template Strand AGC AA3 AA1 AA1 U U U U C G A U A A U C Nucleus • AA2 Cytoplasm AAG

  34. A A T T C G A C T A T G T C G T A A Template Strand AGC AA3 AA1 AA1 AAG U U U U C G A U A A U C Nucleus • AA2 Cytoplasm

  35. A A T T C G A C T A T G T C G T A A Template Strand AGC AA3 AA1 AA1 AAG U U U U C G A U A A U C Nucleus • AA2 Cytoplasm

  36. Mistakes in the Genetic Code • Mutation- a change in the genetic code • Mutagen- any substance that causes a mutation to occur • Examples: chemicals, radiation, high temps

  37. Types of Mutations • 1. Point mutation- change in one base pair, often has no effect on phenotype • Example GGU = glycine GGC = glycine

  38. Types of Mutations • 2. Frame shift mutation- deletion or addition of a base • Codons get shifted Example: GGG CUU CCU ACU Gly Leu Pro Thr Suppose third G in first codon is lost, then: GGC UUC CUA CU Gly Phe Leu

  39. Types of Mutations • 3. Chromosomal mutation- whole chromosome is added or deleted • Caused by non-disjunction

  40. Genetic Technology • Selective breeding- farmers choose organisms with desirable traits to breed • Increases frequency of desired allele in population • Genetic Engineering- faster method of increasing desired allele in population • Small fragment of DNA is cut or cleaved from one organism and fragment is inserted into a host organism • Also called recombinant DNA- connecting fragments of DNA from different sources Transgenic organism- organism containing fragments of foreign DNA

  41. Genetic TechnologyGel Electrophoresis • Fragments of DNA are separated by weight • Matching bands can be used to identify the source of the DNA • Link: http://www.lewport.wnyric.org/jwanamaker/animations/Chrom%26Elpho.html

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