Ran is a small monomeric G protein

That exists in either a GTP-bound or a GDP-bound conformation & provides the energy to drive unidirectional transport of macromolecules through the nuclear pore.

TLS Online TPP Program

#Id: 562

#Unit 2. Cellular Organization

The lac mRNA (as most mRNA is in bacteria) is extremely unstable and decays with a half-life of only 3 minutes.

TLS Online TPP Program

#Id: 563

#Unit 2. Cellular Organization

B-1,6-allolactase is a true inducer of Lac operon which activates Lac ZYA gene expression by inhibiting Lac Repressor

TLS Online TPP Program

#Id: 564

#Unit 2. Cellular Organization

Negative Regulation/ Positive Regulation or catabolic repression

TLS Online TPP Program

#Id: 565

#Unit 2. Cellular Organization

Molecules that induce enzyme synthesis but are not metabolized are called gratuitous inducers such as IPTG

TLS Online TPP Program

#Id: 566

#Unit 2. Cellular Organization

IPTG (isopropyl b-D-1-thiogalactopyranoside) X-gal (5-bromo4-chloro-3-indolyl-b-D-galactopyranoside). When acted on by that enzyme, X-gal releases a blue color that makes it useful as substrate in assays.

       

TLS Online TPP Program

#Id: 567

#Unit 2. Cellular Organization

The lac operon has three paradoxes

1-If the operon is in a repressed state, how does the inducer enter the cell to start the process of induction

2- If the operon is in a repressed state, how Repressor is removed with allolactose 

3- How is allolactose synthesized in Repressed state Answer is Leaky Expression