* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Download Ch 16-17 High
Holliday junction wikipedia , lookup
List of types of proteins wikipedia , lookup
Agarose gel electrophoresis wikipedia , lookup
Promoter (genetics) wikipedia , lookup
Maurice Wilkins wikipedia , lookup
RNA polymerase II holoenzyme wikipedia , lookup
Epitranscriptome wikipedia , lookup
Community fingerprinting wikipedia , lookup
Non-coding RNA wikipedia , lookup
Molecular evolution wikipedia , lookup
Silencer (genetics) wikipedia , lookup
Eukaryotic transcription wikipedia , lookup
Gel electrophoresis of nucleic acids wikipedia , lookup
DNA vaccination wikipedia , lookup
Point mutation wikipedia , lookup
Gene expression wikipedia , lookup
Molecular cloning wikipedia , lookup
Transcriptional regulation wikipedia , lookup
Transformation (genetics) wikipedia , lookup
Non-coding DNA wikipedia , lookup
Artificial gene synthesis wikipedia , lookup
Vectors in gene therapy wikipedia , lookup
DNA supercoil wikipedia , lookup
Cre-Lox recombination wikipedia , lookup
Nucleic acid analogue wikipedia , lookup
Ch. 16 DNA DNA: the Central Dogma, history, structure Replication History: timeline, people and their accomplishments • • • • Mendel (heredity) Thomas Hunt Morgan (flies, linkage) Griffith (1928) transformation and mice Avery and colleagues (1944): – proposed DNA as the transforming agent • Chargaff (late 40’s-early 50’s) – base pairing (AT CG) • Hershey-Chase (1952) DNA IS hereditary material • Watson and Crick (1953) (Franklin) chemical structure of DNA • Meselson-Stahl mid 1950’s – DNA Replication details Griffith: Transformation Hershey / Chase (the hereditary material is not a protein) Radioactive P and S Whose rule? Purine? Pyrimidine? You have 6 billion pair in every cell! A-T C-G How’s it all fit? • DNA coiling – Let’s see it! Chargaff’s Rule • Purines (A, G, double rings) always pair with Pyrimidines (T, C, single rings) • A-T, C-G (& in RNA? ____) • Old AP test question: if in a cell the DNA bases are 17% A’s then what are the %’s of the other bases? • CUT your PY or Pure Silver (Ag) DNA Replication: SEMICONSERVATIVE MODEL How did they (Meselson-Stahl) prove this? FIG 16.10 KNOW: Steps of Replication Enzymes Leading and Lagging strands Okazaki Fragments Anti-parallel Video “Bubbles” Replication forks, simultaneous replication Semi-conservative **Eukaryotes - multiple origins of replication **Prokaryotes have one This process is fueled by… nucleoside triphosphates DNA is made from 5’ to 3’ and it is read from 3’-5’. The 3’ end is the end which elongates (grows) Why is this direction important to consider in Replication? What do the terms 5’ and 3’ mean? Leading & Lagging strands, made 5’-3’ Okazaki fragments ENZYMES: helicase, DNA Polymerase, ligase (are of the lagging strand) Enzymes : •Helicase •Single strand binding proteins •Primase (RNA Primer) •DNA Polymerase •Ligase •Nuclease and DNA Polymerase (both are repair enzymes) Let’s see this in Action • Leading Strand (Nobelprize.org) • Lagging Strand (Nobelprize.org) • Overall (wiley) • Overall 3D view (wehi.edu.au or dnai.org) (Youtube has a music version) Telomeres (Ch.16) Unfilled gap left at the ends of the DNA strands due to the use of RNA primers Eventual shortening of DNA over time Dolly, cancer, HeLa cells (telomerase fig16.19) Enzyme: Telomerase extends the (3’) long strand so the 5’ strand can finish. WOW! ? ? ? Where is telomerase naturally found? DNA from a single skin cell, if straightened out, would be about six feet long but invisible. Half a gram of DNA, uncoiled, would stretch to the sun. Again, you couldn't see it. http://www.pixar.com/featurefilms/nemo/images/index_lwide.jpg Story Time!! (Due Tuesday Nov. 6) Select a figure, process, topic, or high level vocabulary word from chapter 16 or 17. Your job is to make a poster of your selected topic. -The poster should be kid-friendly as to say an intelligent 8-10 year old would be able to understand it yet make sure that all information communicated is true to the text. - Finally, you may not use English, do the best you can, ask friends, relatives, teachers, etc for help if necessary. Potential topics include but are not limited to the following….. Experiments that identified DNA as the “genetic material”, DNA Structure, DNA Replication, Telomers and telomerase, Transcription, Modification of RNA, Translation, Mutations. Ch.17 One gene/One polypeptide Define transcription and translation Compare Prokaryotic and Eukaryotic cells video • (21 different AA’s) • mRNA code • Ave. protein is 400AA long • Titin is 30,000AA long! (this is _____ nucleotides?) • DNA= triplets • RNA= codons • 5’ to 3’ • Pre- mRNA (primar y transcri pt) • Promoter: TATA Box • Transcription factors • RNA polymerase • Transcription initiation complex • Movie Finishing the premRNA Introns: (intruding) spliced out Exons: kept, will be Expressed in the cell • snRNP’s identify introns • Introns are cut out at a Spliceosome • Final mRNA has only genes that will be transcribed in cell no “junk genes” • video • Translation • The production of polypeptides • On a Ribosome • tRNA, transfer RNA carries in the amino acids to the ribosome (transfers the A.A) Read 5’ to 3’ • A P E: • AminoacyltRNA synthetase • Peptidyl tRNA binding site • Exit • Video • Movie Termination of the translation Translation of many polypeptide chains at once The signal mechanism: signal peptides Free or bound ribosomes? • Coupled transcrip tion and translati on One base difference out of 574 Amino acids (1722 bases) The wrong protein Nothing formed •Happy Homecoming (again!) •Have fun, be safe Repairing mistakes