- In what journal did this article appear? When?
This article appeared in “Science” in 1980.
- What is the primary purpose of this paper?
The primary purpose of this paper was to publish the findings of the nucleotide structure of pre-pro-insulin mRNA.
- What is the structural difference between insulin and pro-insulin?
Pro-Insulin is a precursor to insulin. Insulin has the variable C chain, while pro-insulin does not.
- What is complementary DNA (cDNA)?
Complementary DNA is a single strand of DNA that is complementary to m RNA or DNA that has been synthesized from messenger RNA by reverse transcriptase. In this article the cDNA was made from “total human insulinoma mRNA.”
- What are "recombinant plasmids"?
“Recombinant plasmids” are circular pieces of DNA found in some bacteria that contain man-made DNA sequences in them.
- What does the article mean when it says "Escherichia coli x1776 was transformed with the recombinant plasmids"?
It means that the certain strain of E. coli was made into a recombinant plasmid with the insertion of new DNA so that it may be used in this experiment.
- What is meant by the "polyA tail" or "polyadenylation" of a gene?
The “poly-A tail” means the polypeptide attached to the end of chain A.
- What is meant by the statement that "insulin A and B chains are highly conserved"?
The statement “insulin A and B chains are highly conserved” means that the chains are protected from changes in the following generations (they are unchanging).
- Which chain is most highly conserved?
Chain A is the most highly conserved chain.
- What do the researchers believe is the purpose of the C chain?
Researchers believe that the purpose of the C chain is to help form the 3-D shape of the pro-insulin molecule.
- Why does it make sense that the C chain is more variable (less highly conserved) than the A chain and B chain?
The C chain is more variable (and less highly conserved) than the A and B chains because it doesn’t have such specific functions as chains A and B.
- What do the researchers believe is the purpose of the pre-peptide (D chain)?
Researchers believe that the purpose of the pre-peptide (D chain) is to signal the transfer of the pre-pro-insulin protein into the ER.
- How does the human pre-pro-insulin gene differ from rat pre-pro-insulin (rat I and rat II)?
The biggest difference from the human pre-pro-insulin gene and that from the rat are the coding areas.
- What is the first codon in the coding region of the gene (at the start of the pre-peptide) and what is the first amino acid in the polypeptide?
The first codon in the coding region of the gene is: GGA
The first amino acid in the polypeptide is: methionine (met).
The abstract of this article is found here.
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