Termination Transcription stops after the RNA polymerase has moved the length of the gene where it comes into contact with a special sequence of bases in the DNA template called a terminator. General Features Many RNA polymerase molecules can be simultaneously transcribing a single gene on after another. The ability to make multiple transcriptions allows cells to produce particular proteins in large amounts. In eukaryotes one gene per RNA transcript molecule Must be modified before taking part in protein synthesis Must be transported through the nuclear membrane to the ribosomes in the cytoplasm. In prokaryotes, the RNA transcript molecule is essentially in final form, and may be a transcription of several adjacent, related genes.
Noncoding segments comprise most of the DNA in most organisms.
In 1977, scientists found that some noncoding segments actually fall within the boundaries of eukaryotic genes, thus interrupting segments that code for amino acid sequences in polypeptides. This process called RNA splicing or RNA processing , is also required for tRNA and rRNA production. Simultaneous experimentation and discovery by several different groups of scientists. RNA splicing The signals for RNA splicing are sets of a few nucleotides located at either end of each intron. These are small particles located in the cell nucleus that are composed by RNA and protein molecules.