The Ames test uses a strain of S. typhimurium that is mutant for the operon responsible for the biosynthesis of the amino acid histidine. For example, the mutant operon might contain a missense or a frameshift mutation in one of the genes for histidine biosynthesis.

TLS Online TPP Program

#Id: 3205

#Unit 3. Fundamental Processes

.All these systems are prone to introducing errors during the repair process. 

TLS Online TPP Program

#Id: 9653

#Unit 4. Cell Communication and Cell Signaling

Activated dimeric MAP kinase induces transcription of the c-fos gene by directly activating TCF, and indirectly activating SRF.

TLS Online TPP Program

#Id: 5900

#Unit 3. Fundamental Processes

TLS Online TPP Program

#Id: 6362

#Unit 2. Cellular Organization

Activators that stimulate this kind of promoter work by triggering a conformational change in either RNA polymerase or DNA; that is, they interact with the stable closed complex and induce a conformational change that causes transition to the open complex. This mechanism is an example of allostery.

TLS Online TPP Program

#Id: 2482

#Unit 13. Methods in Biology

The polymerization of acrylamide is an example of free-radical catalysis and is initiated by the addition of ammonium persulfate and the base N,N,N′,N′-tetramethylenediamine ( TEMED).