AIIMS&NEET BIOLOGY&CHEMISTRY, &CSIR-NET LIFESCIENCES .:RNA SYNTHESIS

Termination is the completion of RNA synthesis and the disengagement of both the newly synthesized RNA and the RNA polymerase which manufactured it from the DNA template.

steps of RNA synthesis and processing?

In this process, RNA polymerase (RNAP) first binds to a specific DNA sequence (a promoter) that sets the start site for transcription. RNAP then starts RNA synthesis (initiation), proceeds to transcribe through the gene(s) (elongation), and finally stops transcription at a specific site (termination).

protecting 3' end of the RNA.

alternative processing generates different msgs; in transcription, defines the end of the exon.

RNA export.

translation.

the processing steps for messenger RNAs?

Capping at the 5' end.

Addition of a poly(A) tail at the 3' end.

Splicing to remove introns

method of RNA synthesis?

The process of RNA synthesis is known as transcription and the products are called transcripts, simply because the base sequence of the RNA produced reflects the base sequence of the template DNA.

RNA processing pathway?

RNA processing is a tightly regulated, highly complex pathway which includes RNA transcription, pre-mRNA splicing, editing, transportation, translation, and degradation of RNA.

capping and tailing?

Hint: MRNA goes under two additional processes known as capping and tailing. In capping an unusual nucleotide called methyl guanosine triphosphate is added to the 5- end of MRNA. In tailing adenine is added to the 3-end of MRNA process of capping help recognising mRNA by the ribosomes.
site of RNA synthesis?

The Nucleolus

The most prominent substructure within the nucleus is the nucleolus (see Figure 8.1), which is the site of rRNA transcription and processing, and of ribosome assembly. As discussed in the preceding chapter, cells require large numbers of ribosomes to meet their needs for protein synthesis.