DNA and RNA

1. Ch. 12 DNA and RNA

2. DNA: the genetic material • Griffith - 1928, used a bacteria that causes pneumonia to figure out that there are smooth (S) strains and rough (R) strains, the S cells killed mice, while the R cells did not, a mixture of R and S Cells did however kill the mouse, he conclude that there was a transformation from R to S • Avery - 1944, identified molecule that transferred R into S • Hershey and Chase - 1952, discovered that DNA is the transforming factor by using Radioactive Labeling

3. Griffith’s Experiment

4. Hershey and Chase Experiment

5. DNA Structure • Nucleotides - subunits of nucleic acids, contain a 5-carbon sugar, a phosphate, and a nitrogenous base. • DNA • adenine (A), guanine (G), cytosine (C), and thymine (T) • RNA • adenine, guanine, cytosine, and uracil (U) • A and G are double rings so they are called Purine Bases • C, T and U are single rings called Pyrimidine Bases

6. Chargaff • Chargaff - found that the amount of G is equal to the amount of C, and A is equal to T • Chargaff's Rule - G=C, and A=T

7. Structure and Bases

8. Structure and Bases

9. DNA History Con’t • X-ray diffraction - used to figure out the shape of DNA (double helix) • Watson and Crick - Double Helix structure • 1. two outside strands consist of alternating deoxyribose and phospate • 2. cytosine and guanine bases pair to each other by three hydrogen bonds • 3. thymine and adenine bases pair to each other by two hydrogen bonds • A purine always bonds to a pyrimidine base, so A=T and C=G Therefore, C+T = G+A

10. DNA Structure • Top rail goes from the 5' carbon on the left to the 3' carbon on the right ( 5'-3') • Bottom rail goes from the 3' carbon on the left to the 5' carbon on the right (3'-5') • Chromosome Structure • Human chromosomes have anywhere from 51 million to 245 million base pairs

11. DNA Replication • Semiconservative Replication - parental strands of DNA separate, serve as templates and produce DNA molecules that have one strand of parental DNA and one strand of new DNA • DNA Helicase - enzyme responsible for unwinding the DNA, breaks the Hydrogen bonds between the bases • When unzipped RNA primase adds a primer or starting point on each DNA strand • DNA Polymerase - enzyme that adds the nucleotides to the new DNA strand starting at the 3' end and then zips the strands back up

12. DNA Replication

13. DNA Replication Con’t • Chargaff's rule is demonstrated therefore there are exact copies of each other • Leading strand - strand that is copied as the DNA unwinds, built continuously • Lagging strand - replicates in the opposite direction as the DNA unwinds • Okazaki fragments - chunks 100-200 nucleotides long on the lagging strand where replication takes place

14. DNA Replication

15. Nerdy Scientist Pick-Up Line

16. RNA • RNA - contains ribose (sugar), uracil (replaces thymine), and is usually single stranded • mRNA - messenger RNA, formed from one strand of a DNA molecule, they direct the synthesis of specific proteins • rRNA- ribosomal RNA, forms ribosomes in the cytoplasm • tRNA- transport RNA, smaller segments of RNA that transport amino acids to the ribosome

17. RNA • introns- sequences that are not coded for on the DNA molecule • exons - the sequences that are used in the code • DNA ultimately makes proteins, there are also 20 different amino acids that make up proteins • DNA sequences (codes) make up these amino acids • Codon - three base codes in DNA and mRNA that make up amino acids

18. Transcription • Transcription - DNA code is transferred to mRNA in the nucleus, then uses the code to synthesize proteins • Template strand - the strand of DNA that is copied by the RNA • Nontemplate strand - the strand of DNA that is not used by the RNA

19. Translation • Translation - once the mRNA is synthesized and processed, it moves to the ribosome, it attaches to the ribosome and the code is read and translated into proteins • tRNA - is basically an interpreter for the mRNA codonsequence • anticodon - three base coding sequence that is complimentary to the codon sequence

21. Amino Acids

22. What is the Sequence? • Start - Serine - Histidine - Tryptophan - Glycine - Stop • Start - Proline - Asparagine - Isoluecine - Valine - Glutamate - Stop • mRNA~ • AUG - CCG - UUU - GGA - UGG - UGU - GGG - UAA

23. What is the Sequence Con’t • Amino Acids • tRNA • DNA

24. Terms • Gene regulation - ability of an organism to control which genes are transcribed in response to the environment • Operon - section of DNA that acts as an on/off switch for transcription • Mutation - permanent change occur in a cells DNA • point mutation - one base is exchanged for another (substitution) • Frame shift mutation - when a gain or a loss of a base • Duplication - when bases are duplicated • Expanding mutation - repetitive bases • Mutagen - Certain chemicals and radiation that can damage DNA sequences

25. Genetic Mutations

26. Test Info • TEST - 10 questions • Vocabulary with its definition • DNA Helicase, tRNA, DNA polymerase, Codon, rRNA, mRNA, genetic code, ribose, deoxyribose, RNA polymerase, anticodon, replication, transcription, translation, ribosomes, x-ray diffraction, and Hydrogen bond • Historical Contributions • Match the scientist with his/her contributions • Griffith, Avery, Hershey Chase, Franklin, Watson Crick, Chargaff • Comparing Molecules • Compare molecules of DNA, mRNA, and tRNA • know the structure!!!!!!! • Matching Codons • Fill in a table like we did in class • know the DNA, mRNA, tRNA, and the amino acid • Processes • Exactly from our notes • The process of DNA replication, transcription, and translation

27. Book Review • Review • Page 353 #’s: 3-5, 8-11, • Pg.354 #’s: 17, 18, 26-28, 30, 34 Pg.356-357 #’s: 1-5, 9, 10, 12, 13, 16-18