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What controls the transcription of an operon?
Instead, they also contain regulatory DNA sequences that control transcription of the operon. The promoter is found in the DNA of the operon, upstream of (before) the genes. When the RNA polymerase binds to the promoter, it transcribes the operon and makes some mRNAs.
What would enable a single RNA transcript?
What would enable a single RNA transcript to be translated into different polypeptides? The RNA transcript can be spliced more than one way. In a eukaryotic cell an abnormal protein is binding to the promoter for a gene.
How is transcription controlled in eukaryotes?
As in bacteria, transcription in eukaryotic cells is controlled by proteins that bind to specific regulatory sequences and modulate the activity of RNA polymerase. …
What is positive control of gene expression?
An operon is a cluster of coordinately regulated genes. In the case of positive control, the genes are expressed only when an active regulator protein, e.g. an activator, is present. Thus the operon will be turned off when the positive regulatory protein is absent or inactivated.
Which part of the operon controls whether transcription is on or off?
the operator
There’s a short DNA segment here, and it’s called the operator. This is the part of the operon that acts as a switch for transcription. It’s just like an operator that works the switchboard for a telephone company. The operator controls whether or not transcription will occur.
What is transcriptional gene control?
In molecular biology and genetics, transcriptional regulation is the means by which a cell regulates the conversion of DNA to RNA (transcription), thereby orchestrating gene activity. This control allows the cell or organism to respond to a variety of intra- and extracellular signals and thus mount a response.
Where does transcriptional control occur?
In Summary: Post-TransCRIPTIONAL Control of Gene Expression Post-transcriptional control can occur at any stage after transcription, including RNA splicing, nuclear shuttling, and RNA stability. Once RNA is transcribed, it must be processed to create a mature RNA that is ready to be translated.
How does RNA regulate gene expression?
RNA binding proteins (RBPs) are another such class of proteins. They bind short RNA sequences to regulate gene expression posttranscriptionally by regulating the splicing of precursor mRNA as well as the stability, transport, translation, and decay of mature mRNA (2).
What controls gene expression?
Gene expression is primarily controlled at the level of transcription, largely as a result of binding of proteins to specific sites on DNA. The promoter gene doesn’t encode anything; it is simply a DNA sequence that is initial binding site for RNA polymerase.
What is the first level of control of eukaryotic gene transcription?
What is the first level of control of eukaryotic gene transcription? the binding and unbinding of transcription factors to enhancer sequences RNA splicing DNA packing and unpacking attachment of RNA polymerase to the promoter
How are prokaryotes different from bacteria in transcription?
Prokaryotes and eukaryotes perform fundamentally the same process of transcription, with a few significant differences (see Table 11.3 ). Eukaryotes use three different polymerases, RNA polymerases I, II, and III, all structurally distinct from the bacterial RNA polymerase. Each transcribes a different subset of genes.
How is RNA polymerase used to transcribe genes?
Transcription in Bacteria Bacteria use the same RNA polymerase to transcribe all of their genes. Like DNA polymerase, RNA polymerase adds nucleotides one by one to the 3’-OH group of the growing nucleotide chain.
Which is part of DNA is transcribed into RNA?
During the process of transcription, the information encoded within the DNA sequence of one or more genes is transcribed into a strand of RNA, also called an RNA transcript.