BPS 3101 Lecture Notes - Lecture 2: Edwin Southern, Electric Dipole Moment, Ionic Strength

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tealgerbil756

11 Nov 2017

School

University of Ottawa

Department

Biopharmaceutical sciences

Course

BPS 3101

Professor

Christopher Boddy

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Document Summary

Genomics lecture 2: lots of things that can be done with the mrnas. This does occur to modify the proteins can be expressed. This is really important in the context of trnas and ribosomal rnas. Transfer rnas many of the the nuclear bases and nucleotides are chemically modified and methylated. There is a very large amount f chemical modifications that has to occur to ribosomal and trna . helps them maintain stability: mrnas or rnas can be processed. Slide 5: we have the coding strand and the template strand, when we transcribe that we melt the dsdna. Jus al(cid:449)ays i(cid:374)di(cid:272)ate (cid:449)hi(cid:272)h e(cid:374)ds a(cid:396)e 5" o(cid:396) (cid:1007)": atg o(cid:396) aug is the sta(cid:396)t (cid:272)odo(cid:374) a(cid:374)d that"s (cid:449)he(cid:396)e t(cid:396)a(cid:374)slatio(cid:374) sta(cid:396)ts. But aug encodes (cid:373)ethio(cid:374)i(cid:374)e (cid:449)hi(cid:272)h (cid:272)a(cid:374)"t o(cid:272)(cid:272)u(cid:396) i(cid:374)side p(cid:396)otei(cid:374) (cid:272)odi(cid:374)g (cid:396)egio(cid:374)s. o it does(cid:374)"t al(cid:449)ays (cid:373)ea(cid:374) it"s a start codon. Sometimes it occurs within an open reading frame (a protein coding gene).

Related Questions

My instructor sent me this in an email to study for a final.Please help me construct the best possible answer for this as Ihave not written a satisfactory answer to the first question allsemester.

1) As you know the final does include a comprehensive componentregarding the gene and genome. (80 pts)

This first question has to be extremely detailed. For example,"A gene is a unit of inheritance. The gene carries information forit to be passed from one generation to the next. When you combine agene with the environment you are five the necessities for aphenotype. There are many gene types and elements such as the genesfor RNAs that carry information to make proteins, genes fortransfer RNAs that carry amino acids to the ribosomes, genes forribosomal RNAs that are required for structure, function andactivities of a ribosome, genes for small nuclear RNAs that make upthe spliceosome and help to splice introns, and the genes fortelomerase RNA component (TERC). A gene must also include manyparts such as introns, exons, core promoters, regulatory promoters,activators, downstream promoter enzymes (DPE), and many others.These parts of the genes as well as the different gene types mustallow for some variation in certain conditions to allow evolutionto occur. A gene must also be able to be passed on, or inheritedfrom one generation to the next." Figures and drawings are alsoappreciated by my instructor. If you could basically just throweverything you can think of within a gene or a genome at thisquestion that would be greatly appreciated.

2) You will also need to study genetic mapping, DNA as a digitalstorage device, X chromosome inactivation and synthetic biology.(35 pts)

sapphireeel99

A single base substitution in the anticodon loop of one of thetRNAs for glutamic acid (tRNAglu) can hypothetically generate amutant tRNA that is able to suppress translational termination bycausing insertion of a glutamic acid residue at certain terminationcodons. Such mutant tRNAs are in fact encountered in nature and arereferred to as suppressor tRNAs. Assume that there are two tRNAgenes for glutamic acid (so that this hypothetical mutation wouldnot be lethal) and that one of these tRNAs acquires a single basemutation in its anticodon loop. Assume also that this tRNA has a Uresidue at the wobble position (and can therefore base pair withboth Glu codons) and that the mutation does NOT occur at thiswobble position.

A) What is the nucleotide sequence of the wildtype anticodon oftRNAglu (5â?3â polarity) and what is the mutant sequence that wouldhave the properties described above?

Wt sequence:

Mutant sequence:

B) At which stop codons would the mutant tRNAglu be able tosuppress translational termination? (assume that G-U base pairingis possible at the wobble position)

C) Mutations of the sort described above are rarely encountered innature, due in part to the existence of a key step in the chain ofevents that helps ensure translational fidelity. What is this stepand how might it prevent suppressor tRNAs from being able toincorporate amino acids at stop codons?

ochrehedgehog380

I just came across this abstract:

Aminoacyl-tRNA synthetases (aaRSs) are responsible for creatingthe pool of correctly charged aminoacyl-tRNAs that are necessaryfor the translation of genetic information (mRNA) by the ribosome.Each aaRS belongs to either one of only two classes with twodifferent mechanisms of aminoacylation, making use of either the29OH (Class I) or the 39OH (Class II) of the terminal A76 of thetRNA and approaching the tRNA either from the minor groove (29OH)or the major groove (39OH). Here, an asymmetric pattern typical ofdifferentiation is uncovered in the partition of the codonrepertoire, as defined by the mechanism of aminoacylation of eachcorresponding tRNA. This pattern can be reproduced in a uniquecascade of successive binary decisions that progressively reducescodon ambiguity. The deduced order of differentiation is manifestlydriven by the reduction of translation errors. A simple rule can bedefined, decoding each codon sequence in its binary class, therebyproviding both the code and the key to decode it. Assuming that thepartition into two mechanisms of tRNA aminoacylation is a relicthat dates back to the invention of the genetic code in the RNAWorld, a model for the assignment of amino acids in the codon tablecan be derived. The model implies that the stop codon was alwaysthere, as the codon whose tRNA cannot be charged with any aminoacid, and makes the prediction of an ultimate differentiation step,which is found to correspond to the codon assignment of the 22ndamino acid pyrrolysine in archaebacteria.

Granted, this is a few years old, but I often find myself havingto admit that "I don't know" when at the root of discussions onevolution. That is, once abiogenesis has occurred, we can go on andexplain the rich diversity of life, but sadly we really don't knowmuch before that critical step. Generally, those satisfied with"magic" as an answer posit their myths and fables, whereas I'drather try to actually find out what happened. Sadly, as theabstract shows, you actually need a level of education tounderstand papers such as this that is generally well beyond thosewho would deny the reality of evolution.

Does anyone have a collection of papers on abiogenesis that aremore accessible and understandable to laypeople?

BPS 3101 Lecture Notes - Lecture 2: Edwin Southern, Electric Dipole Moment, Ionic Strength

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