1. Nucleic Acid Structure and Organization Asmarinah Department of Medical Biology

2. Nucleic acid - Macromolecules consisting of a chain of nucleotides joined together by phosphodiester bonds - divided into: DNA (Deoxyribonucleic acid) molecules RNA (Ribonucleic acid) molecules

3. DNA and its building DNA is made from subunits, called nucleotides Each nucleotide consisting of -Sugar (deoxyribose) -Phosphate -Base: Adenine Thymine Guanine Cytosine

6. DNA - Gene A gene is defined as a segment of DNA that contains the insctruction for making a particular protein

8. ● DNA molecules are organized into chromosome ● Chromosome: A DNA molecule with its attendant proteins that moves as an independent units during mitosis and meiosis Before DNA replication, each chromosome consists of a single DNA molecule plus protein, is called a chromatid After replication, each chromosome consists of two identical DNA molecule plus proteins; this are called sister chromatids ● Chromatin: DNA plus the proteins that package it within the cell nucleus

9. ABC A.The principal structural features of chromosome B.An electron micrograph of human mitotic chromosomes C.A diagram of various classes of human chromosomes

10. Chromatin packing occurs on several levels

11. Structural organization of nucleosome Nucleosome contains Octameric histon protein & DNA double helix

12. Genome The totality of genetic information belonging to a cell or an organism; in particular, the DNA that carries this information Genomics The science of studying the DNA sequences and properties of entire genomes

15. Each human chromosome has a unique banding pattern Human Genome

16. The Organization of human genome

18. Conserved gene order in chromosome between the human (a) and mouse (b) genome

19. Closely related species can have very different chromosome numbers

20. Chromosomes from many eucaryotes (including human) contain a large excess of interspersed DNA that does not seem to carry critical information, called junk DNA  This DNA may not be important, but can play a role: - as spacer material - for long-term evolution of the species - for the proper expression of genes Bacteria and some single-celled eucaryotes have especially compact genomes. The complete nucleotide sequence of their genomes reveals that DNA molecules are little more than strings of closely packed genes

21. Mitochondrial DNA Chromosome No. 25 Chromosome No. 25 Genome  circular double stranded DNA Genome  circular double stranded DNA Maternal inherited Mito DNA : 16.569 bp Mito DNA : 16.569 bp Nuclear DNA : 3 x 10 9 bp Nuclear DNA : 3 x 10 9 bp

22. The structure of mitochondria - contains two membranes: * outer mitochondrial membrane * inner mitochondrial membrane -There is two aqueous compartment: * Matrix, within the interior * Intermembrane space, between OMM and IMM

23. produce ATP 5 respiration enzyme complexes complex I (NADH oxydoreductase : Ubiquinone) complex II (suksinat oxydoreductase : ubiquinone) complex III (ubiquinol oxydoreductase : sitokrom c) complex IV (Cytocrome c oxydase) complex V (ATPsynthase). Role of mitochondria

24. The genome of E. coli A.E.coli strain K-12 has 4.639.221 nucleotides pairs B.A diagram of the E. coli genome. E. Coli genome is circular that forms a single, closed loop. Yellow or orange bars shows protein-coding genes Green arrows indicate genes encoding only RNA molecules

25. Genetic differences between pathogen and nonpathogen bacteria

26. Example: Genetic organization of Vibrio cholerae A. Vibrio cholerae has two circular chromosomes, that each of its has distinct origin of replication (oriC1 & oriC2) CTXφ locus carriers the gene for cholera toxin VPI island contains gene for factors required for intestinal colonization B. Map of CTX φ locus consist of: - core region: gene for cholera toxin ctxA & ctxB gene for involving of virulence (ace & zot) - repeated sequence RS2 & RS1 that involved chromosomal insertion of bacteriophage genome

27. Schematic drawings of several types of viral genomes

28. RNA Polymer formed from covalently linked ribonucleotide monomer Type of RNA: -mRNA = messenger RNA, code for protein -rRNA = ribosomal RNA, form basic structure of ribosome and catalyze protein synthesis -tRNA = tranfer RNA, central to protein synthesis as adaptors between mRNA and amino acids

29. -snRNA = small nuclear RNA, function an variety of nuclear process -snoRNA = small nucleolar RNA, used to process and chemically modify rRNA -scaRNA = small cajal RNA, used to modify snoRNA and snRNA -miRNA = microRNA, regulate gene expression typically by blocking translation of selective mRNA -siRNA = small interfering RNA, turn off gene expression by directing degradation of selective mRNA and the establishment of compact chromatin structure

30. mRNA

32. References: -Albert et al., 2008. Molecular biology of the cell. 5 th ed. -Albert et al., 2004. Essential of cell biology. -Pollard and Earnshaw. 2004. Cell biology.