Lecture 4I. Proteins A. functions follows StructureII. Nucleic Acids Monomer PolymerNucleic Acid Nucleotide DNA(double stranded) RNA(single stranded)A. Monomer is a nucleotide1. A sugari. ribose in RNAii. Deoxyribose in DNA2. Phosphate group3. Nitrogenous basei. DNAa. A G U Cii. RNAa. AT G CB. Nucleotides are attached together into chains by a phosphodiester bondsv ia a condensation reaction C. Synthsis of Nucleic Acid Polymers1. joined by phosphodiester bondsi. phosphate group on 5’C of sugae linked to hydroxyl on 3’C or next sugar chain2. Sugar-phosphate backbone of nucleic acid chain has polarity:i. 5’ phosphate endii. 3’ hydroxyl end 3. The template determines the sequence of bases, which provides the genetic information.III. Bases in RNA and DNAA. Pyrimidine Bases1. thymine2. Cytosine3. UracilB. Purine Bases1. Adenine2. GuanineC. In a nucleic acid, ach base is attached to wither a ribose or a deoxyibose by the bondIV. DNAA. Charactericstics1. two strand of nucleotides in a double helix2. strands oriented in opposite directions(antiparallel)3. bases point inside the helix (sugarphosphate outside)4. opposing bases “pair” by hydrogen bondingB Purines and Pyrimidines pair inorder to maximaze hydrogen bondsC. as a result of the antiparlelle structure of DNA major and minor grooves are present. DNA binding proteins interact with the bases in the groves because the backbones are not in the wayD. forces that stabilize DNA1. phosphodiester bonds2. Hydorgen bonds3. base stacking contributes to the stability of DNAE. Erwin Chargaff1. %G=%C and %A=%TF. Heat denatures DNA1. heat breaks hydrogen bonds denatures or melts dsDNA into ss2. ssDNA and dsDNA differ in absorbance of UV at 2604. temperature cools single strands anneal forming dsDNA againV. Genetic InformationA. Passed from parent to offspringB. determines the charcyteristcs (phenotype) of the organismC. The Chromosomal Theory of Inheritance (1900)1. gentic info is located in chromosomws2. chomosme are made of DNA and protein VI. Griffiths Experiment-Transformation of StreptococcusA. Streptococcus is a pathogenic bacterusB. Two strains-one is pathogenic or virulent and the other is nor pathogenic or nonvirulentC. Virulent strain= S starin1. Mouse diedD. Nonvirulent starin=R strain1. Mouse is healthyE. Heat Killed S cells (control)1. Mouse healthyF. Mixture of heat –killed S cells and living R cells 1. Mouse dies2. Living S cells are found in blood sampleG. dead s bacteria contained a substance or transforming factor that thansformed R bacteris into pathogenus S strainVII. Evidence for DNA as the Genetic MaterialA. Avery, McCarty, Macleod Experiment1. Treatment with Dnase abolishes transofomation anility2. purified DNA is able to transform R strain3. DNA is the transforming FactorB. DNA component of T2 virus is injected into the host cell1. virsus- particle made of protein and nucleis acid that uses cells to replicate2. Phage(Bacteriophage)- Virsu that infects bacteria3. protein contains S not P and DNA contains P and not S4. this shows that DNA and not protein gets inside the cells5. DNA not protein is passed onto progeny (offspring)VIII. DNA FunctionsA. Copy Functions1. fathifully copied prior to cell divisionB. Expression Function1. Encodes cellular productes that determine phenotypeC. Replication1.DNARNAProtein2. known as the central