Precursor cell (or simply precursors), is widely used to denote any ancestral cell type (either stem cell or progenitor cell) of a particular lineage.

TLS Online TPP Program

#Id: 767

#Unit 3. Fundamental Processes

Abortive transcription is when RNA Polymerase makes short transcripts, typically shorter than 10 nucleotides (nt), while still bound at the promoter.

TLS Online TPP Program

#Id: 768

#Unit 3. Fundamental Processes

In abortive transcription, an RNA chain forms without movement of the enzyme down the template by scrunching DNA

 

TLS Online TPP Program

#Id: 769

#Unit 3. Fundamental Processes

After release of the abortive product, the enzyme again begins synthesizing RNA at position +1 called as Initiation

TLS Online TPP Program

#Id: 770

#Unit 3. Fundamental Processes

Once an enzyme makes a transcript longer than 10 nucleotides, it is said to have escaped the promoter. At this point, it has formed a stable ternary complex, containing enzyme, DNA, and RNA. This is the transition to the elongation phase.

TLS Online TPP Program

#Id: 771

#Unit 3. Fundamental Processes

During RNA transcript formation, DNA makes its 90° turn at the active site.

TLS Online TPP Program

#Id: 772

#Unit 3. Fundamental Processes

In the core polymerase active site, Process of the nucleotide addition cycle and undergoing translocation takes place by a Brownian ratchet mechanism.