An uncatalyzed keto– enol tautomerization reaction occurs quite slowly as a result of the high free energy of its carbanion-like transition state called as

TLS Online TPP Program

#Question id: 13089

#Unit 13. Methods in Biology

To express a yeast gene in E. coli, your task is to design a strategy to insert the yeast gene into the bacterial plasmid. Below is a map of the area of the yeast genome surrounding the gene in which you are interested.

 

The distance between each tick mark placed on the line above is 100 bases in length

Below are the enzymes you can use, with their specific cut sites shown 5’-XXXXXX-3’ 3’-XXXXXX-5’

 

The plasmid is 5,000 bases long and the two farthest restriction enzyme sites are 200 bases apart. The plasmid has an ampicillin resistance gene somewhere on the plasmid distal from the restriction cut sites.

                              

You do the digestion of the insert and the vector and then ligate the two digestions together. You then transform the ligation into bacteria and select for ampicillin resistance. You get three colonies on your transformation plate. You isolate plasmid from each one and cut each plasmid with the enzyme XbaI. You then run your three digestions on an agarose gel and see the following patterns of bands. Describe what each plasmid actually was that was contained in each of the three colonies.

 

What is the Colony 2’s plasmid is;

TLS Online TPP Program

#Question id: 4333

#Unit 3. Fundamental Processes

The anticodon of a particular tRNA molecule is

TLS Online TPP Program

#Question id: 15638

#Unit 13. Methods in Biology

You have isolated two mutations that show decreased expression of the Lac operon. However, unlike like the promoter mutations, these mutations don’t respond to the inducer IPTG. These mutations, designated Lac3– and Lac4–, are evaluated for the quantity of ß-galactosidase and permease activity expressed with or without IPTG:

 

Mapping experiments reveal that Lac3– and Lac4– are different short deletions located in the region before the start of the LacZ gene. Given the data shown above suggest which genetic element(s) in addition to part of the promoter has been deleted in each mutant. 

TLS Online TPP Program

#Question id: 4233

#Unit 3. Fundamental Processes

A particular triplet of bases in the coding sequence of DNA is AAA. The anticodon on the tRNA that binds the mRNA codon is __.

TLS Online TPP Program

#Question id: 12781

#Unit 10. Ecological Principles

Subtraction of which of the following will convert gross primary productivity into net primary productivity?