In cilia and flagella,

microtubules are assembled from an MTOC called a basal body.

TLS Online TPP Program

#Id: 2289

#Unit 3. Fundamental Processes

higher temperature favors tighter binding between RNA polymerase holoenzyme and T7 DNA

TLS Online TPP Program

#Id: 2290

#Unit 3. Fundamental Processes

RNA polymerase holoenzyme binds DNA loosely at first

a. Binds at promoter initially

b. Scans along the DNA until it finds one

TLS Online TPP Program

#Id: 2291

#Unit 3. Fundamental Processes

Isomerization, does not require energy derived from ATP hydrolysis and is instead the result of a spontaneous conformational change in the DNA– enzyme complex to a more energetically favorable form. 

TLS Online TPP Program

#Id: 2292

#Unit 3. Fundamental Processes

Isomerization is essentially irreversible and once complete, typically guarantees that transcription will subsequently initiate .

TLS Online TPP Program

#Id: 2293

#Unit 3. Fundamental Processes

Formation of the closed complex, in contrast, is readily reversible: polymerase can as easily dissociate from the promoter as make the transition to the open complex.

TLS Online TPP Program

#Id: 2294

#Unit 3. Fundamental Processes

During initial transcription, the polymerase remains stationary on the promoter, unwinds downstream DNA, and pulls that DNA into itself