This set of notes is long If you want to find notes for a specific date ex 3 17 or topic initiation press Ctrl F on your keyboard Command F for Mac users and type in what you want to find It ll search the document for whatever specific word phrase you typed in and save you the time of scrolling through everything PCB 3063 General Genetics Lecture Notes Exam 3 Start Exam 3 Pairing G C 3 bonds A T 2 bonds easier to break A U in RNA Fri 3 7 Nucleotide bases G guanine C cytosine A adenine T thymine U uracil replaces T in RNA Pyramidine C and T also U smaller Purine G and A larger DNA has 2 deoxyribose sugar RNA has ribose sugar Polymer DNA RNA chain long Runs 5 3 DNA read 3 5 and written 5 3 DNA must have replication storage expression mutation variation Griffith experiment Injected mice w deadly bacteria to see if they d live Smooth bacteria killed rough lived heated smooth lived Rough heated smooth killed Discovered transformation rough bacteria took on properties of smooth Inspired research to figure out what transformation factor was Scientists were down to 2 possible answers DNA or protein McCarty experiment Took smooth bacteria centrifuged it heated it separated it out from solution Removed carbs lipids protein stripped it bare Took samples of it added dif enzymes and put it with living rough bacteria Added protease ate away protein rough bacteria became smooth Added ribonuclease ate ribosomes rough bacteria became smooth Added deoxyribonuclease ate DNA rough bacteria stayed same Results pointed to DNA as transforming factor Hershey Chase experiment Wanted to see if DNA or protein is used to copy viruses Used radioactive labels to mark DNA and protein P32 DNA phosphate used to build DNA structure S35 protein sulfur used in protein structure Put virus in solution w E coli to infect and one of the radioactive markers Let virus reproduce and infect fresh set of E coli After 2nd reproduction examined empty viral shells infected bacteria new viruses P32 solution shells unlabeled bacteria labeled new viruses labeled Viral DNA passed on to infected bacteria and new virus copies S35 solution shells labeled bacteria unlabeled new viruses unlabeled Viral proteins stayed within the virus s shell Showed DNA was transforming factor DNA strand absorbs the most UV light at wavelength 260 nm Protein absorbs the most at 280 nm Used to prove that DNA is the heritable factor At 260 nm DNA mutates the most DNA alphabet analogy 4 letters nucleotides 3 letters per word trinucleotide 64 words 20 amino acids There are many words in a sentence Each sentence means a protein Melting Double stranded DNA splits into 2 single strands Anneal 2 single strands combine into d stranded DNA Matching base pairs recombine Repetitive sequences anneal faster than unique ones Replication Initiation start at origin of replication replicon Elongation adding on bases as copy is being written added 5 3 Proofreading exonuclease removes mismatched bases Required template DNA polymerase enzyme deoxynucleotides 3 OH primer attached DNA polymerase builds DNA Primer bit of RNA attaches itself shows where to start dATP deoxy adenine triphosphate 1 deoxyribose sugar 1 base like adenine 3 phosphate groups Replication fork where DNA helix unzips Sense strand leading runs 3 5 fast copying storage nontemplate Antisense strand lagging runs 5 3 Okazaki fragments usable template Okazaki fragments bits of DNA that were copied in pieces need to be attached DNA strands are antiparallel run in opposite directions Conservative replication new strand just like old one Dispersive replication new old strands made from pieces of each other Semi conservative replication new strand made from old strand template Correct method Meselson Stahl experiment Worked with E coli which use N14 in their body structure Put N14 E coli in N15 let them integrate the heavier atoms into system replicate Put N15 labeled E coli into N14 solution Centrifuged solution to see how much heavier the cells became Centrifuge spin test tube around v fast heavier bits collect at bottom Results pointed to semi conservative replication Taylor s experiment Took DNA chromosomes and exposed to radiation Took pictures that revealed radioactivity When they divided both sister chromatids had radioactive labels When they divided again one had the labels and the other was fresh Results pointed to semi conservative replication Constancy population has almost identical genes Central dogma DNA RNA protein Retroviruses RNA DNA RNA protein retro backwards RNA virus RNA 1 RNA 2 protein DNA RNA library analogy DNA is like a library You can t check out any of the books but you can read them If you need information for something you have to write it down transcription You find the book you re looking for and open it initiation Then you take out your notebook and copy down what it says elongation Your handwriting is different than the book s use U for T in RNA You stop when you ve written everything you need termination Then you leave and use the info for whatever you needed it for protein synthesis DNA RNA molecule Nucleotide base G C A T U Pentose sugar 5 of them deoxyribose DNA ribose RNA Phosphate group Mon 3 17 Chargoff s Rule purines pyrimidines G or A C or T A T not C G Watson Crick observations of DNA Double stranded Strands made of DNA polymers held by hydrogen bonds Helix spiral Anti parallel both strands run in opposite directions Complimentary bases on one strand mirrored by those on the other DNA structure Primary 1D single strand sequence of single polymer Secondary 2D bent strand local folding in a given area Tertiary 3D structure of single molecule Quaternary 4D orientation of 2 molecules to each other Base pair made of 1 purine 1 pyrimidine Space of 3 4 angstroms between paired bases One complete twist of helix 34 angstroms 10 base pairs Helix width 20 angstroms 2 nanometers B DNA usual form of DNA Right handed helix Z DNA left handed helix mostly G C bases A DNA when purified from salty environment DNA has a negative charge RNA Transcription use DNA template to make RNA writing down instructions Translation use RNA to make protein following instructions Replication use RNA template to make another RNA making another copy of instructions Goes only up to secondary structure Stem and loop shape Complimentary bases pair up bend strand saves energy Single stranded mRNA messenger has instructions to build protein tRNA transfer carries amino acid used to build protein rRNA ribosomal
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