2. DNA Replicationand Protein Synthesis

3. Central Dogma of Gene Expression

4. DNA Deoxyribonucleic AcidDeoxyribonucleic Acid –Controls cells activities –Contains organism’s traits –Contains messages to produce proteins

5. DNA Monomer- Nucleic AcidMonomer- Nucleic Acid

6. DNA

7. DNA – 4 bases Purines Pyrimidines Adenine bonds with Thymine Guanine bonds with Cytosine

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

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

10. DNA Structure Then ladderThen ladder is twisted forming a double helix

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

12. DNA Replication Steps to DNA replicationSteps 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

13. DNA Replication

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

15. DNA Replication Links http://www.lewport.wnyric.org/j wanamaker/animations/DNA%20 Replication.htmlhttp://www.lewport.wnyric.org/j wanamaker/animations/DNA%20 Replication.htmlhttp://www.lewport.wnyric.org/j wanamaker/animations/DNA%20 Replication.htmlhttp://www.lewport.wnyric.org/j wanamaker/animations/DNA%20 Replication.html

16. DNA and RNA DNARNA Strands Double strand Single strand SugarDeoxyriboseribose Base pairs A-TC-GA-UC-G Uracil is substituted for thymine

17. DNA and RNA

18. 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”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.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 proteinrRNA- ribosomal RNA- bonds with mRNA, site where tRNA brings amino acids to form a protein

19. Types of RNA mRNA rRNA tRNA

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

21. Protein Synthesis Transcription 1. DNA unzips1. DNA unzips 2. Free floating nucleotides bond to one side of DNA (Uracil bonds with Adenine)2. Free floating nucleotides bond to one side of DNA (Uracil bonds with Adenine) 3. Bases are joined together3. Bases are joined together 4. mRNA leaves the nucleus and enters the cytoplasm4. mRNA leaves the nucleus and enters the cytoplasm

22. Protein Synthesis Translation Codon- set of three bases, each one codes for one amino acidCodon- set of three bases, each one codes for one amino acid

23. Protein Synthesis Translation Determine the chain of Amino Acids for the following codons AUG CAG UAU GAU GUU UUA CCU UAG Methionine GlutamineTyrosineAspartateValineLeucineProlineStop

24. Protein Synthesis Steps of Translation 1. Ribosome attaches to mRNA1. Ribosome attaches to mRNA 2. tRNA with anti-codon that is the complement of the codon attaches to mRNA carrying a specific amino acid2. tRNA with anti-codon that is the complement of the codon attaches to mRNA carrying a specific amino acid 3. Ribosome slides to second codon3. Ribosome slides to second codon 4. Second tRNA with complementary anti- codon bonds with second codon4. Second tRNA with complementary anti- codon bonds with second codon 5. Amino acid from 1 st tRNA bonds with amino acid attached to 2 nd tRNA5. Amino acid from 1 st tRNA bonds with amino acid attached to 2 nd tRNA 6. Ribosome continues down mRNA creating a chain of amino acids until a stop codon is reached6. Ribosome continues down mRNA creating a chain of amino acids until a stop codon is reached

25. Protein Synthesis Steps of Translation

26. Protein Synthesis links http://www.lewport.wnyric.org/j wanamaker/animations/Protein% 20Synthesis.htmlhttp://www.lewport.wnyric.org/j wanamaker/animations/Protein% 20Synthesis.htmlhttp://www.lewport.wnyric.org/j wanamaker/animations/Protein% 20Synthesis.htmlhttp://www.lewport.wnyric.org/j wanamaker/animations/Protein% 20Synthesis.html http://www.wisc- online.com/objects/index_tj.asp? objid=AP1302http://www.wisc- online.com/objects/index_tj.asp? objid=AP1302http://www.wisc- online.com/objects/index_tj.asp? objid=AP1302http://www.wisc- online.com/objects/index_tj.asp? objid=AP1302

27. U C G U U C A A A mRNA A G C TTC A A A T G C AA T TG T template Strand

28. U C G U U C A A A mRNA A G C TTC A A A T G C AA T TG T template Strand Nucleus Cytoplasm Ribosome

29. A G C TTC A A A T G C AA T TG T Template Strand Nucleus Cytoplasm U C G U U C A A A U C G U U C A A A mRNA

30. U C G U U C A A A A G C TTC A A A T G C AA T TG T Template Strand Nucleus Cytoplasm AA1 AGC tRNA’s

31. U C G U U C A A A A G C TTC A A A T G C AA T TG T template Strand Nucleus Cytoplasm AA1 AGC tRNA’s

32. U C G U U C A A A A G C TTC A A A T G C AA T TG T template Strand AA2 AAG AA1 AGC tRNA’s Nucleus Cytoplasm ATP

33. U C G U U C A A A A G C TTC A A A T G C AA T TG T Template Strand AA3 U U U AA2 AAG AA1 Nucleus Cytoplasm AGC AA1 ATP

34. U C G U U C A A A A G C TTC A A A T G C AA T TG T template Strand AA3 U U U AA2 AAG AA1 Nucleus Cytoplasm AGC AA1

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

36. U C G U U C A A A A G C TTC A A A T G C AA T TG T Template Strand AA3 U U U AA2 AAG AA1 Nucleus Cytoplasm AGC AA1

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

38. Types of Mutations 1. Point mutation- change in one base pair, often has no effect on phenotype1. Point mutation- change in one base pair, often has no effect on phenotype Example GGU = glycineExample GGU = glycine GGC = glycine GGC = glycine

39. Types of Mutations 2. Frame shift mutation- deletion or addition of a base2. 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

40. Types of Mutations 3. Chromosomal mutation- whole chromosome is added or deleted3. Chromosomal mutation- whole chromosome is added or deleted –Caused by non-disjunction

41. Genetic Technology Selective breeding- farmers choose organisms with desirable traits to breedSelective 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 populationGenetic 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

42. Genetic Technology Gel Electrophoresis Fragments of DNA are separated by weightFragments of DNA are separated by weight Matching bands can be used to identify the source of the DNAMatching bands can be used to identify the source of the DNA Link: http://www.lewport.wnyric.org/j wanamaker/animations/Chrom% 26Elpho.htmlLink: http://www.lewport.wnyric.org/j wanamaker/animations/Chrom% 26Elpho.html http://www.lewport.wnyric.org/j wanamaker/animations/Chrom% 26Elpho.html http://www.lewport.wnyric.org/j wanamaker/animations/Chrom% 26Elpho.html