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Lac

Lac

a resinous substance produced mainly on the banyan tree, but to some extent on other trees, by the coccus lacca, a scale-shaped insect, the female of which fixes herself on the bark, and exudes from the margin of her body this resinous substance.

Stick-lac is the substance in its natural state, incrusting small twigs. When broken off, and the colouring matter partly removed, the granular residuum is called seed-lac. When melted, and reduced to a thin crust, it is called shell-lac or shellac. Lac is an important ingredient in sealing wax, dyes, varnishes, and lacquers. Ceylon lac, a resinous exudation of the tree Croton lacciferum, resembling lac. Lac dye, a scarlet dye obtained from stick-lac. Lac lake, the colouring matter of lac dye when precipitated from its solutions by alum. Mexican lac, an exudation of the tree Croton draco.

Origin: Per. Lak; akin to Skr. Laksha: cf. F. Lague, It. & NL. Lacca. Cf. Lake a colour, lacquer, litmus.


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Determine whether gene lac I and lac O is functioning?

My sample is treated in 3 ways: No inducer, with lactose , with IPTG. ONPG is used in all sample to determine the beta galactosidase. I know that both lactose and IPTG can associate with lac repressor and cause expression. If the result of these ...

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by eos
Fri May 09, 2014 11:57 am
 
Forum: General Discussion
Topic: Determine whether gene lac I and lac O is functioning?
Replies: 0
Views: 581

Secondary Sugars(metabolism/sugar/bacteria/Lac Operon)

What are secondary sugars? I'm studying for the final tomorrow and we are focusing a lot on the lac operon series and some of the metabolic processes of sugars. I know that bacteria cells prefer galactose, but will still use lactose, so does that mean lactose is a secondary ...

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by Vulpess
Mon Dec 16, 2013 3:40 am
 
Forum: Microbiology
Topic: Secondary Sugars(metabolism/sugar/bacteria/Lac Operon)
Replies: 2
Views: 1788

RNA

... trans-acting regulatory elements are in essence transcriptional regulators/promoter sequences that are categorized based on acting distance. The lac operon in E.coli is a typical example of a cis-acting element. Promoter sequences that regulate expression of the genes contained within the operon ...

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by nukeman
Thu Mar 28, 2013 2:21 pm
 
Forum: Molecular Biology
Topic: RNA
Replies: 6
Views: 15698

Lac operon, e.coli expression vectors and biotechnology uses

How can gene regulation and expression be manipulated for designing expression vectors? And as a result, what are their potential biotechnological applications?

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by luna2000
Fri Jan 18, 2013 10:51 pm
 
Forum: Molecular Biology
Topic: Lac operon, e.coli expression vectors and biotechnology uses
Replies: 1
Views: 1320

Lac operon and bioinformatics

I am trying to incorporate bioinformatics regarding the lac operon. Any ideas as to how? I'm looking at the e. coli cells changing from a glucose medium to a lactose medium?

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by luna2000
Fri Jan 18, 2013 8:10 pm
 
Forum: Bioinformatics
Topic: Lac operon and bioinformatics
Replies: 0
Views: 1445
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