1. Dr. Kathleen Hill Assistant Professor Department of Biology The University of Western Ontario khill22@uwo.ca Office Hours: Monday 1 to 5pm Room 333 Western Science Centre Research Website: http://www.uwo.ca/biology/Faculty/hill/index.htm

2. Genomes DNA Genes to Proteins Kathleen Hill January 18 Lecture/Workshop January 25 th Lab Tour WSC 333

3. The human genome is a multi-volume instruction manual The GENOME is a multi-volume instruction manual Each CHROMOSOME is a volume of text Genes are a chapter of text in the volume The text is written in a chemical language that has a four letter alphabet A,C,G,T NUCLEOTIDES

4. Our instruction manual can be read in our DNA GenomeChromosomeGene DNA sequence Manual Volume Chapter Text

5. 46 chromosomes 22 pairs of autosomes 1 pair of sex chromosomes Human Genome Male Karyotype

6. Human nuclear DNA is highly packaged in chromosomes

7. DNA has a double helix structure

8. Nitrogenous Bases The DNA language alphabet

9. Key Concepts Complementary Two key properties of nucleic acids 5’ 3’ 5’ Antiparallel ACGT TGCA ACGT TGCA

10. Complementary Antiparallel

11. Chromosome Landscape Chromosome Gene DNA sequence Single nucleotides 10 6 to 10 8 nucleotides millions of nucleotides

12. Landscape of a chromosome Genes occupy little landscape on a chromosome

13. Viruses are “nonliving” and have the greatest diversity in genome types ssDNA dsDNA ssRNA dsRNA single molecules multiple molecules

14. Bacterial Genomes Single molecules, circular dsDNA Smaller circular plasmid genomes - extragenomic

15. Bacterial Genomes Single molecules, circular dsDNA Smaller circular plasmid genomes - extragenomic Genetic information can be exchanged between bacteria via plasmids and between the plasmid and the bacterial chromosome

16. Bacterial Genomes Single molecules, circular dsDNA Smaller circular plasmid genomes - extragenomic Viruses can infect bacteria and add genetic information to the bacterial host chromosome

17. Bacterial Genomes Single molecules, circular dsDNA Smaller circular plasmid genomes - extragenomic Genome is not enclosed in a separate compartment in the prokaryotic cell Genomic DNA is not protein packaged

18. Eukaryotic Cell: Genome is contained in separate cell compartment

19. Eukaryotic Genomes Protein packaged Membrane compartmentalized

20. Genome Animal Cell

21. Mitochondrial DNA Double stranded Circular Located in the mitochondrion

22. Genomes of closely related organisms show more similar organization

23. Genome Size

24. Genome Size and Number of Genes Human Genome: 3.4 billion nucleotides

25. Continuous Discontinuous Differences in Gene structure

26. Continuous Discontinuous Exons produce message; introns do not

27. Eukaryotic Genes are interrupted by noncoding intronic sequence Genes of mammals have more intronic sequence than flies, yeast and bacteria

28. GENES

29. Certain Information in the DNA sequence is processed to result in proteins that can carryout an essential cell function Gene

30. One strand of the DNA sequence (the template) is written into a intermediate message Messenger RNA

31. One strand of the DNA sequence (the template) is written into a intermediate message Messenger RNA (mRNA)

32. mRNA Single stranded Complex secondary structure Complementary sequence shows hydrogen bonding

34. A distinguishing feature of mRNA is the polyA tail

35. The message is then translated into a new language Amino acids are a 20 letter alphabet of the protein language

36. One code used to translate from nucleic acid to protein sequence Each codon will be translated to an amino acid

37. tRNA is the translator amino acid carrier Carries the anticodon The anticodon is complementary to the codon

38. Site of translation on the t-RNA

39. Amino acids are linked together in a protein chain

40. Overview of the key players in translation

41. In nucleus In cytoplasm In eukaryotes In prokaryotes the process occurs simultaneously on same mRNA strand