dna: the genetic material
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DNA: The Genetic Material. DNA. Deoxyribonucleic Acid. DNA Polymer : Nucleotide Monomer Each Nucleotide has 3 parts: 1) 5 carbon sugar Deoxyribose 2) Phosphate group PO 4 3) Nitrogen Base. Identifying the Genetic Material. - PowerPoint PPT PresentationTRANSCRIPT
DNA: The Genetic DNA: The Genetic MaterialMaterial
DNADNADeoxyribonucleic AcidDeoxyribonucleic Acid
DNA DNA Polymer : Nucleotide Polymer : Nucleotide MonomerMonomer
Each Nucleotide has 3 parts:Each Nucleotide has 3 parts: 1) 5 carbon sugar 1) 5 carbon sugar Deoxyribose Deoxyribose 2) Phosphate group 2) Phosphate group PO PO44 3) Nitrogen Base3) Nitrogen Base
Nitrogen Bases
Purines Pyrimidines
Adenine Guanine Thymine Cytosine
Identifying the Genetic Identifying the Genetic MaterialMaterial Experiments of Griffith and Avery Experiments of Griffith and Avery
yielded results that suggested DNA yielded results that suggested DNA was genetic material (1944)was genetic material (1944)
Hershey & Chase Hershey & Chase used the used the bacteriophage T2 bacteriophage T2 and radioactive and radioactive labels to show that labels to show that virus genes are virus genes are made of DNA, not made of DNA, not protein (1952)protein (1952)
DNA stores information that tells cells DNA stores information that tells cells which proteins to make and when to make which proteins to make and when to make themthem
DNA forms a spiral DNA forms a spiral ladder ladder Double Helix Double Helix
Double helix is held Double helix is held together by weak together by weak Hydrogen bondsHydrogen bonds
Erwin Chargaff Erwin Chargaff DiscoveryDiscovery Chargaff’s Chargaff’s RuleRule A=T, G=C A=T, G=C
AA TT GG CCHumaHumann
3030 3030 1919 1919
PlantPlant 2727 2727 2222 2222VirusVirus 2121 2222 2828 2727
Rosalin FranklinRosalin Franklin
The Structure of DNAThe Structure of DNA Discovered by Discovered by
Watson & Crick in Watson & Crick in 1953 1953
received Nobel received Nobel Prize in 1962 along Prize in 1962 along with Maurice with Maurice WilkinsWilkins
DNA ReplicationDNA Replication Phase of Cell Cycle? Phase of Cell Cycle?
Why replicate?Why replicate? Step 1: DNA Helicase Step 1: DNA Helicase
unzips DNA by breaking unzips DNA by breaking weak Hydrogen bonds.weak Hydrogen bonds.
Step 2: DNA Step 2: DNA polymerase adds polymerase adds nucleotides to exposed nucleotides to exposed nitrogen bases.nitrogen bases.
Step 3: Two DNA Step 3: Two DNA molecules form that are molecules form that are identical to original.identical to original.
DNA is referred to as “Semi-DNA is referred to as “Semi-conservative”, Each DNA molecule conservative”, Each DNA molecule 1 template & 1 new strand1 template & 1 new strand
DNA polymerase proofreads DNA DNA polymerase proofreads DNA during its replication so that very few during its replication so that very few errors occurerrors occur
The secrets of the sequenceThe secrets of the sequence
http://www.youtube.com/wahttp://www.youtube.com/watch?v=sf0YXnAFBs8tch?v=sf0YXnAFBs8