negative inducible operon

. The repressor-inducer complex fails to join with the operator gene, which is turned on. The three structural genes are expressed as three enzymes to metabolise lactose to galactose and glucose. Lactose, thus, acts as the inducer for its own breakdown. When the concentration of..

This is a type of operon which is switched on when a chemical, called inducer, is present. The inducer is almost always a substrate. This operon has following componen..

In 1961, two French microbiologists, Francois Jacob and Jacques Monod proposed a mechanism, called Operon Hypothesis , for the regulation of gene action in E. coli. It got them the Nobel Prize in 1965. fig. 23.1 - Francois Jacob and Jacques Monod with their Colleague They found that..

This gene is located adjacent to the operator gene. It has two functions. 1.The promoter gene marks the site at which the RNA polymerase enzyme binds. When the operator gene is turned on, the enzyme moves over the operator gene to reach the structural genes and the transcription of mRNA starts. 2...

Protein synthesis is a controlled process in which a given protein is synthesised in the cell only when it is necessary. When a particular protein is to be synthesised the specific gene has to express and initiate transcription. The mechanism that stimulates the expression of certain genes ..

Inducible operon system consists of structural genes (cistrons), operator gene can either switch on or switch off the structural genes by allowing or not allowing RNA polymerase molecules found attached to promoter gen..

Explanation of Induction - When the positively charged body is brought near the two cans A and B, the electrons (-ve charges) from both the cans are attracted and get concentrated on B which is near R. The can A which has lost the electrons is left with an equal amount of positive charge. When the ..

. Thus both the leaves L and M, now have similar negative charge and they repel each other. Hence the leaves diverge. Note that the induced charge at the near end is always opposite to the inducing char..

Lenz's Law - The motion of the magnet in either direction causes a change in strength of the magnetic field linked with the coil and this causes a current to be induced in the coil. This induced current opposes the change in the magnetic field by producing its own magnetic field..

Gene Regulation in Eukaryotes - In eukaryotes, the genes that code for the enzymes needed to catalyse the various steps of a particular metabolic pathway may not be adjacent or even be in different chromosomes. However, these genes are regulated by operon model as in bacteria. Both the ..