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'''Week 2: Article Critique'''

:'''Critique: [[Metabolic pathway|Metabolic Pathway]]'''
:: The article seems neutral overall. ''Lehninger principles of biochemistry'' is cited, as is another biochemistry textbook. There are also multiple journal articles cited, which also tend to be neutral. The links all appear to be functional. 

:: The article claims that "Glycolysis was the first metabolic pathway discovered," but it does not provide a source for this claim, so a citation is needed here. There are multiple places in the Overview section that require citations. There is also some awkward wording in this section. 


:'''Critique: [[Bioenergetics]]'''
:: There are not nearly enough citations for this article (this is also reflected by the warning banner at the top of the article). Also, all of the citations are journal articles. It would be helpful to have a citation from a textbook as well. I also feel like the overview section could be a lot more concise. The article does not seem biased, but it's really hard to tell with so little citations.

:: Overall, it's difficult to evaluate the other parts of the article, because of the lack of citations. There are a lot of links present, which appear to be working. However, these do not make up for the citation issue.


'''Plans for Wikipedia Article'''

[[Crick, Brenner et al. experiment|''':Crick, Brenner et al. experiment''']] 

:I think that this article would benefit from being reorganized. I might divide the information into different sections (importance, the experiment, etc.). There are also lots of improvements that could be made content-wise. More citations are needed, and the experiment itself is cited in this article, which (I may be incorrect) I believe to be bad practice. Overall, this article reads more like a direct summary of the original scientific paper, and does not provide any new information on how the study has been influential in modern research.


=Editing Article=

'''Proposed Edits'''

{{Expert-subject|Biology|date=November 2008}}

The '''Crick, Brenner et al. experiment''' (1961) was a [[scientific experiment]] performed by [[Francis Crick]], [[Sydney Brenner]], [[Leslie Barnett]] and R.J. Watts-Tobin. This study demonstrated that the [[genetic code]] is made up of a series of three base pair codons which code for individual amino acids. The experiment also elucidated the nature of [[gene expression]] and [[frame-shift mutation]]s. 

=The Experiment=

In the experiment, [[proflavin]]-induced [[mutation]]s of the [[T4 phage|T4]] [[bacteriophage]] gene, rIIB, were isolated. Proflavin causes mutations by inserting itself between [[DNA bases]], typically resulting in insertion or deletion of a single base pair.<ref>{{Cite journal|last=Brenner|first=S.|last2=Benzer|first2=S.|last3=Barnett|first3=L.|date=1958-10-11|title=Distribution of Proflavin-Induced Mutations in the Genetic Fine Structure|url=https://www.nature.com/nature/journal/v182/n4641/pdf/182983a0.pdf|journal=Nature|language=en|volume=182|issue=4641|pages=983–985|doi=10.1038/182983a0|issn=0028-0836}}</ref> 

Through the use of Proflavin, they were able to insert or delete base pairs into their sequence of interest. When nucleotides were inserted or deleted, the gene would often be nonfunctional. However, if three basepairs were added or deleted, the gene would remain functional.<ref name=":0">{{Cite journal|last=Yanofsky|first=Charles|date=2007-03-09|title=Establishing the Triplet Nature of the Genetic Code|url=http://www.cell.com/cell/fulltext/S0092-8674(07)00253-X|journal=Cell|language=English|volume=128|issue=5|pages=815–818|doi=10.1016/j.cell.2007.02.029|issn=0092-8674}}</ref> This proved that the genetic code uses a [[codon]] of three DNA bases that corresponds to an [[amino acid]]. The mutants produced by Crick and Brenner that could not produce functional rIIB protein were the results of [[frameshift mutation]]<nowiki/>s, where the triplet code was disrupted.  

Brenner and Crick et al. were also able to correct their frameshift mutations through the use of Proflavin. If they had a nonfunctional gene due to a deleted base pair, by inserting a [[Base pair|basepair]] into the general area of the deleted one, they were able to rescue the function of the gene. This is because the bases were shifted back into the correct r[[Reading frame|eading frame]]. <ref name=":0" />  

=Implications= 

The demonstration of the triplet nature of the genetic code, although carried out with bacteriophage, later proved to be universally applicable to all forms of life.<ref name=":1">{{Cite journal|last=Koonin|first=Eugene V.|last2=Novozhilov|first2=Artem S.|date=2017-05-06|title=Origin and evolution of the genetic code: the universal enigma|url=http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3293468/|journal=Iubmb Life|volume=61|issue=2|pages=99–111|doi=10.1002/iub.146|issn=1521-6543|pmc=PMC3293468|pmid=19117371}}</ref>   

The results of this experiment inspired many to begin decoding the triplet code discovered by Brenner and Crick et al. Once this paper was published in 1961, researchers knew that there are 64 possible triplet codons, since there are four nitrogenous bases (4 x 4 x 4 = 64). Today, scientists have decoded what all 64 codons encode for, and the assignments have proven to be nearly universal.<ref name=":1" />  

==See also==
*[[Nirenberg and Leder experiment]]
*[[Nirenberg and Matthaei experiment]]

==Notes==
<references />

==References==
*{{cite journal |doi=10.1038/1921227a0 |author=[[Francis Crick|Crick FH]], [[Leslie Barnett|Barnett L]], [[Sydney Brenner|Brenner S]], Watts-Tobin RJ |title=General nature of the genetic code for proteins |journal=Nature |volume=192 |issue= 4809|pages=1227–32 |date=December 1961 |pmid=13882203 |bibcode=1961Natur.192.1227C}}
*Sydney Brenner (Author), Lewis Wolpert (Contributor), Errorl C. Friedberg (Contributor), Eleanor Lawrence (Contributor) 2001 My Life in Science: Sydney Brenner, A Life in Science 2001 Biomed Central Ltd (publisher) {{ISBN|0954027809}}  {{ISBN|978-0954027803}}

{{History of biology}}

[[:Category:Genetics experiments|Crick, Brenner et al. experiment, The]]
[[:Category:1961 in science]]

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