TLS Online TPP Program

#Id: 3412

#Unit 3. Fundamental Processes

SOS response in E. coli:

When DNA is extensively damaged (such as by UV light), DNA replication is halted and the number of single-strand gaps in the DNA increases.

RecA protein binds to this damaged, single-stranded DNA, activating the protein’s co-protease activity.

While bound to DNA, the RecA protein facilitates cleavage and inactivation of the LexA repressor. When the repressor is inactivated, the SOS genes, including RecA, are induced;

TLS Online TPP Program

#Id: 5931

#Unit 10. Ecological Principles

Food web- consists of all the food chains in a single ecosystem

TLS Online TPP Program

#Id: 1205

#Unit 7. System Physiology – Animal

During female reproductive cycle, Estrogen stimulate rapid proliferation of the stromal cells and the epithelial cells of endometrium, before ovulation.

TLS Online TPP Program

#Id: 5058

#Unit 3. Fundamental Processes

Each DnaB–DnaC complex consists of six DnaC monomers bound to a hexamer of DnaB.

Note that the DnaB helicase cannot open double-stranded DNA; it can only unwind DNA that has already been opened, in this case by DnaA.

DnaB binding to single-stranded DNA is the signal to hydrolyze ATP and for release of DnaC.

TLS Online TPP Program

#Id: 1767

#Unit 4. Cell Communication and Cell Signaling

Tolerogens- Antigens that induce tolerance