3 Griffith’s Experiments (2) 1928A mouse injected w/ both heat killed S (virulent) and R types can cause pneumoniaA HEREDITARY FACTOR must be released and taken into the R typeIs this factor protein? DNA? RNA?
4 Avery’s Experiments 1940’s Wanted to determine if the material that was transforming was protein, DNA or RNAProtease to destroy proteinInjected w/heat killed S cells and R cellsAble to transform R to SRNase to destroy RNADNase to destroy DNANot able to transform R to S
5 Hershey-Chase Experiment 1952Protein or DNA?Little protein foundin viruses; all theDNA was presentDNA!!!!!
6 The Structure of DNA Sugar-Phosphate Backbone Nitrogen Bases Deoxyribose (sugar found in DNA)Nitrogen BasesAdenineThymineGuanineCytosine
7 The Structure of DNA (2) Purine Pyrimidine Double ringed baseGuanine and ThyminePyrimidineSingle ringed baseCytosine and AdeninePurines must pair with pyrimidines so the helix can be made (it can twist)
8 DNA Deoxyribonucleic acid Contains genes that code for proteins Involved in heredity
9 AdenineNitrogen base in both DNA and RNAPurine that pairs with thymine in DNA and uracil in RNA
10 GuanineNitrogen base in both DNA and RNAPurine that pairs with cytosine in both DNA and RNA
11 ThymineNitrogen base in DNA onlyPyrimidine that pairs with adenine
12 CytosineNitrogen base found in both DNA and RNA
13 Deoxyribose5 carbon sugar found in DNAMakes up the backbone of DNA (sides of the ladder)
14 Phosphate GroupBackbone of DNAAlternates with deoxyribose
15 Hydrogen BondsBond that joins the nitrogen bases together
16 Building block of nucleic acids Contains… NucleotideBuilding block of nucleic acidsContains…5 carbon sugarNitrogen basePhosphate group
20 DNA Helicase Enzyme responsible for the untwisting of DNA Starts the replication process
21 DNA PolymeraseEnzyme responsible for attaching the nucleotides in the correct order during replication.
22 DNA RNA Deoxyribose Double stranded Thymine One version Ribose Single strandedUracil3 versionsSugar-Phosphate backboneNucleic Acids Adenine, Guanine, Cytosine
23 Steps in replicationDNA helicase unwinds the DNA molecule at several spotsBreaks the hydrogen bonds between the basesDNA polymerase adds new nucleotides2 new strandsOriginal strand + new strand = semiconservative model
24 Structure of RNA Uracil – nitrogen base found only in RNA (pyrimidine) Ribose – 5 carbon sugar found only in RNA
25 Types of RNAtRNA - transfermRNA - messengerrRNA - ribosomal
26 tRNA Used to carry amino acids to codons on mRNA Contains the anticodons on one end and an amino acid on the other end
27 mRNA Contain codons Made through transcription in the nucleus Read by the tRNA during translation in the ctyoplasm
28 Transcription Vs. Translation Transcription – process of making RNA from DNA in the nucleus of the cellTranslation – process of making proteinstRNA recognizes codons of the mRNA and attaches the amino acids in the correct sequence for the protein that DNA coded for.
29 Codon Set of 3 bases found on mRNA Complementary to the anticodon on the tRNA
30 Anticodon Set of 3 bases found on a tRNA molecule Recognizes the codon on mRNA during translation
31 Amino Acid Building block of a protein 20 different kinds (essential and nonessential)
32 Peptide BondBond that joins amino acids together in the growing polypeptide chain
33 Polypeptide Made through translation Growing chain of amino acids that transforms into a protein
34 RNA PolymeraseEnzyme responsible for attaching RNA nucleotides in the correct order.
35 Steps of Transcription (in the nucleus) DNA is the templateRNA polymerase adds the RNA nucleotidesUracil replaces ThymineOnce transcribed, mRNA leaves the nucleus and enters the cytoplasmHooks up with a ribosome to begin translation
36 Steps of Translation Ribosome, mRNA and tRNA needed to begin Anticodon on tRNA matches with the codon on mRNAAlways begins w/ start codon (AUG)Adjacent amino acids form peptide bondstRNA keeps adding amino acids until the stop codon is read
37 Steps of TranslationtRNA releases the polypeptide chain (it will fold and become a functional protein)“naked” tRNA molecules find more amino acids and the process starts all over (as certain proteins are needed)