Genetic Material Taryono Faculty of Agriculture Gadjah Mada University

Definition All biological substances which control the process in organism and able to be transmitted to the progeny 1.Carbohydrate 2.Fat 3.Protein 4.DNA - RNA Biological Substances

Gregor Johan Mendel (1865) Gregor Johan Mendel (1865) Discovered genetics (Modes of Heredity) Discovered genetics (Modes of Heredity) Which substance is the genetic material?

Walter Sutton (1902) Walter Sutton (1902) Discovered Chromosomes Discovered Chromosomes Which substance is the genetic material?

Thomas Hunt Morgan (1910) Thomas Hunt Morgan (1910) Discovered how genes are transmitted through chromosomes Discovered how genes are transmitted through chromosomes Which substance is the genetic material?

Fred Griffith (1928), Microbiologist Fred Griffith (1928), Microbiologist Diplococcus pneumonieae (ball shaped bacterium) Diplococcus pneumonieae (ball shaped bacterium) Two naturally occurring strains have markedly different properties Two naturally occurring strains have markedly different properties 1. The virulent smooth (s) strain → a smooth polysaccharide capsule that is essential for infection 2. The non virulent rough (r ) strain → lacks of outer capsule, giving its surface a rough appearance Which substance is the genetic material?

Griffith’s experiment (1928) The discovery of transformation

Oswald T. Avery, Colin Mcleod, Maclyn McCarty (1944) Expand Griffith experiment Mixed R strain with DNA from S strain and isolated S bacteria Added DNase which broke down DNA and prevented R bacteria from transforming to S bacteria Proteases (broke down proteins) did not inhibit transformation DNA was determined to be the “transforming principle” Which substance is the genetic material? ”

Avery, MacLeod, and McCarty (1944) “Transforming substance is DNA”

Erwin Chargaff (1947) Erwin Chargaff (1947) He found the complementary relationship between the nucleotide in each pair He found the complementary relationship between the nucleotide in each pair Adenine always pairs with thymine and cytosine always pairs with guanine Adenine always pairs with thymine and cytosine always pairs with guanine Which substance is the genetic material?

Rosalind Elsie Franklin (1948) Rosalind Elsie Franklin (1948) Research led to the discovery of the double helix structure of DNA Research led to the discovery of the double helix structure of DNA She took the clearest X-ray diffraction photo of DNA She took the clearest X-ray diffraction photo of DNA Which substance is the genetic material?

Alfred Hershey, Martha Chase (1952) → Blender Experiment Used T2 bacteriophages (phages), a virus that infects bacteria Radiolabeled the bacteriophage with S35 (Protein) and P32 (DNA) Bacterial cells were infected and put in a blender to remove phage particles √ DNA, not protein, is the hereditary material √ Expt: sulfur(S) is in protein, phosphorus (P) is in DNA; only P was found in host cell

Hershey and Chase (1952)

James Watson and Francis Crick (1953) James Watson and Francis Crick (1953) They described the DNA molecule from Franklin’s X-ray and discovered DNA They described the DNA molecule from Franklin’s X-ray and discovered DNA Which substance is the genetic material?

DNA is Genetic Material DNA encodes all the information in the cell The composition of the DNA is the same in all cells within an organism   Variation among different cells is achieved by reading the DNA differently DNA contains four bases that encode all the information to make a bacteria or a human In some viruses the genetic material is RNA

How is Information Encoded in DNA? DNA Consists of four kinds of bases (A,C,G,T) joined to a sugar phosphate backbone Bases carry the genetic information while the phosphate backbone is structural Two complementary strands of bases (C-G) and (A-T)

DNA is a Polymer of Deoxyribonucleotide Units DEOXYRIBONUCLEOTIDE

Deoxyribonucleic Acid (DNA) Nucleotide : Phosphate group Phosphate group 5-carbon sugar 5-carbon sugar Nitrogenous base Nitrogenous base

DNA Nucleotide O O=P-O OPhosphate Group Group N Nitrogenous base (A, G, C, or T) (A, G, C, or T) CH2 O C1C1 C4C4 C3C3 C2C2 5 Sugar Sugar(deoxyribose)

DNA Double Helix Nitrogenous Base (A,T,G or C) “Rungs of ladder” “Legs of ladder” Phosphate & Sugar Backbone

DNA Double Helix P P P O O O P P P O O O G C TA

DNA is Composed of Four Different Ribonucleotides AdenineGuanine ThymineCytosine Two Purines Two Pyrimidines

Nitrogenous Bases PURINES PURINES 1.Adenine (A) 2.Guanine (G) PYRIMIDINES PYRIMIDINES 3.Thymine (T) 4.Cytosine (C) T or C A or G

BASE-PAIRINGSBASE-PAIRINGS Base # of Purines PyrimidinesPairs H-Bonds Adenine (A) Thymine (T)A = T 2 Guanine (G) Cytosine (C)C G 3 CG 3 H-bonds

BASE-PAIRINGSBASE-PAIRINGS CG H-bonds T A

Base Pairing Occurs Through Hydrogen Bonds A-T G-C

Chargaff’s Rule Adenine must pair with Thymine Adenine must pair with Thymine Guanine must pair with Cytosine Guanine must pair with Cytosine Their amounts in a given DNA molecule will be about the same. Their amounts in a given DNA molecule will be about the same. G C TA

Backbone Sugar Molecules Deoxyribose (DNA)Ribose (RNA) 1´ 2´ 3´ 4´ 5´ 1´ 2´ 3´ 4´ 5´ Ribose= Five Carbon Sugar Molecule Deoxy ribo nucleotide

The DNA Backbone is a Deoxyribose Polymer Deoxyribose sugars are linked by Phosphodiester Bonds 5´ 3´ 5´ 3´ 2´ 1´ 5´-p3´-OH 5´3´

5´ 3´ 5´ 3´5´ 3´ 5´ 3´ 5´ 3´ 2´ 1´

5´ 3´ 5´ 3´ 2´ 1´ Base 5´ 3´ 5´ 3´ 2´ 1´

(dATP) Deoxyadenosine 5´-triphosphate DeoxyRibonucleotide DeoxyRibonucleoside Deoxyadenosine

5´ 3´5´ 3´ T C T A G A

= GC AT

Double-stranded DNA Forms a Double Helix

Central Dogma of Biology

DNA, RNA, and the Flow of Information Translation Transcription Replication

Central Dogma (Modifications) Transcription Translation DNA (1)Reverse transcription Replication RNA (2)Self Replication Protein (3)Self Replication (2)Ribozymes