1 / 7

Gene Expression Regulation in Prokaryotic and Eukaryotic Cells

Explore how gene expression is controlled in both prokaryotic and eukaryotic cells, from the regulation of transcription to mRNA processing. Learn about operons, promoters, operators, regulatory DNA sequences, transcription factors, enhancers, silencers, introns, splicing, capping, and tailing.

bruceclark
Download Presentation

Gene Expression Regulation in Prokaryotic and Eukaryotic Cells

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. KEY CONCEPT Gene expression is carefully regulated in both prokaryotic and eukaryotic cells.

  2. Prokaryotic cells turn genes on and off by controlling transcription. • A promotor is a DNA segment that allows a gene to be transcribed. • An operator is a part of DNA that turns a gene “on” or ”off.” • An operon includes a promoter, an operator, and one or more structural genes that code for all the proteins needed to do a job. • Operons are most common in prokaryotes. • The lac operon was one of the first examples of gene regulation to be discovered in bacteria. • The lac operon has three genes that code for enzymes that break down lactose.

  3. The lac operon acts like a switch. • The lac operon is “off” when lactose is not present. • The lac operon is “on” when lactose is present.

  4. Eukaryotes regulate gene expression at many points. • Different sets of genes are expressed in different types of cells. • Transcription is controlled by regulatory DNA sequences and protein transcription factors.

  5. Transcription is controlled by regulatory DNA sequences and protein transcription factors. • Most eukaryotes have a TATA (made of 7 nucleotides) box promoter. • Enhancers and silencers speed up or slow down the rate of transcription. • Each gene has a unique combination of regulatory sequences.

  6. RNA processing is also an important part of gene regulation in eukaryotes. • mRNA processing includes three major steps.

  7. mRNA processing includes three major steps. • Introns are removed and exons are spliced together. • A cap is added. • A tail is added.

More Related