Already have an account? Get multiple benefits of using own account!
Login in your account..!
Remember me
Don't have an account? Create your account in less than a minutes,
Forgot password? how can I recover my password now!
Enter right registered email to receive password!
What is Prokaryotic Gene Expression ?
Control of prokaryotic gene expression occurs primarily at the level of transcription. Prokaryotic genes are arranged in units consisting of a regulator gene and associated units called operons. An operon consists of a promotor site, an operator site, and structural genes. The regulator gene, adjacent to the promotor and operator sites, produces repressors, protein molecules that bind to the operator site, preventing the attachment of RNA polymerase and the start of transcription of structural genes.
The concentration of certain enzymes, called inducible enzymes, is very much dependent upon the concentration of substrate in the cell. For example, in E. coli, the concentration of beta-galactosidase enzyme is very low in a lactose-free environment, but a large increase of the enzyme proportional to the lactose added to the growth medium is produced by a gene segment called the lac operon.
In high concentrations of lactose, inducer sugar molecules bind to the lac repressors and detach them from the operator, allowing RNA polymerase to bind and protein synthesis to occur. Two other proteins are produced along with beta-galactosidase - a permease and a transacetylase. The beta-galactosidase cleaves lactose into glucose and galactose; the permease facilitates transport of lactose across the bacterial cell membrane. The function of the transacetylase is not clear. When the lactose level decreases, repressors bind to the operator site and the operon becomes inactive.
Explain the Voges Proskauer (VP) Test? As it has been discussed in previous exercise, second group of enteric bacteria produces acid during early incubation which rapidly conve
For a sample containing both protein and nucleic acid, the absorbance measured at a particular wavelenght will be the sum of contributions from both types of molecule. using the pr
classification of excretory organs in helminthes, nermatodes, annelids, molluscs, arthropods and echinodems
PGA as the first CO2 fixation product was discovered in photosynthesis of: 1. Bryophyte 2. Gymnosperm 3. Angiosperm 4. Alga Alga
What is the difference between ectoparasite and endoparasite? Ectoparasites are parasites that explore the external surface of the host (as, for example, mites that parasite th
Define crucial periods of a woman's life - pregnancy and lactation? In this unit, we studied about the most crucial periods of a woman's life, pregnancy and lactation, especial
what is the function of the bladder in the bladder worm
Define Changes in Food due to Concentration Process? Obviously concentration that exposes food to 100°C or higher temperatures for prolonged periods can cause major changes in
WHAT IS HEART? AND WHAT THEY DO WORK IN OUR BODY.
Define Principle for Estimation of cholesterol - Lipids? Zlatkis and associates have evolved a method of quantitative determination of cholesterol based on a reagent containing
Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!
whatsapp: +91-977-207-8620
Phone: +91-977-207-8620
Email: [email protected]
All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd