BCHM 3050 1st Edition Exam 3 Study Guide Lectures 20 26 Lecture 20 February 27 What are the basic steps of PCR First denaturation occurs by heating the DNA at 90 95 degrees C for 1 3 minutes in order to separate the DNA strands The next step is called annealing in which the temperature is decreased to 40 50 degrees C to allow the primers to join to the strands Extension is the final step and it involves heating to 70 degrees C for about 5 minutes What is the difference between telomeres and telomerase Telomeres recruit telomerase enzyme and telomerase brings in an RNA template in with it so that the DNA polymerase can fill in the rest of the nucleotides Lecture 21 March 4 What was the name and basic idea of the proposal made by Beadle and Tatum in 1941 They were the one to propose that for every gene there is one enzyme we know this to not be true now because one gene can influence many enzymes and one enzyme can influence many genes This idea was called one gene one enzyme What were the differences of the three mutants used in their experiment Mutant 1 Arg1 without ornithine Mutant 2 Arg2 without citrulline Mutant 3 Arg3 without arginine Lecture 22 March 6 What is the TATA box TATA box is a promoter region located at 25 bases from the start sight in the promoter region of eukaryotes ALL eukaryote genes have this It is universal and highly conserved across eukaryotes What is the function of TFIIH It phosphorylates the RNA polymerase puts phosphate group onto RNA polymerase II and activates it which is critical for eukaryotes to carry out transcription Lecture 23 March 9 What is the significance of the codon AUG The start AUG in eukaryotes codes for methionine in prokaryotes it codes for N formyl methionine Methionine AUG is the start codon and must be present in order for amino acids to be coded in the body start translating where there is an AUG and ignore everything that comes before this start codon How do you calculate the total number of possible base combinations of an organism You must take the total number of bases and raise it to the power of the number of bases that have to be combined to make an amino acid so if you have 4 nucleotide bases and 3 together make a codon than 43 64 which gives you the total number of possible base combinations or codons Lecture 24 March 11 How does a peptide bond form Movement of the ribosome requires energy which is required by EF G GTP Moves completed tRNA to E site tRNA with multiple amino acids sits at P site and leaves A site empty again as ribosome slides Name some transitional differences in eukaryotes versus prokaryotes Eukaryote ribosome is heavier and more complicated Eukaryotes processing capping removing introns occurs which doesn t occur in prokaryotes Shine Dalgarno recognized by the rRNA in prokaryotes Prokaryote transcription is much faster Lecture 25 March 13 Describe some differences in the formation of heterochromatin versus euchromatin Deacetylation and methylation form heterochromatin while acetylation and demethylation form euchromatin Heterochromatin is a form of negative regulation and euchromatin is a form of positive regulation Lecture 26 March 23 How is chromosome 19 an example of epigenetic regulation This occurs on chromosome 19 IGF2 and H19 are on the same chromosome inherit one from mom and one from dad One can be turned off and passed onto offspring Mom s IGF2 is silenced and Dad s H19 is silenced across all humans Example of epigenetics that is not affected by the environment If you do not express H19 Angelman Syndrome no H19 mental disabilities and sterility issues If IGF2 is silenced Prader Willi Syndrome no IGF2 What is alternative RNA splicing Body makes one huge RNA strand with introns and exons Then the spliceosome enzyme complex regulates which mRNA to create based on the exons included in splicing alternate splicing
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