AP Notes, Outlines, Study Guides, Vocabulary, Practice Exams and more!

Operon

Pearson Ch. 18 - Regulation of Gene Expression

Subject: 
Rating: 
0
No votes yet

Ch 18 - Regulation of Gene Expression Overview: Conducting the Genetic Orchestra Prokaryotes and eukaryotes alter gene expression in response to their changing environment In multicellular eukaryotes, gene expression regulates development and is responsible for differences in cell types RNA molecules play many roles in regulating gene expression in eukaryotes Concept 18.1: Bacteria often respond to environmental change by regulating transcription metabolic control occurs on two levels cells can adjust the activity of enzymes already present feedback inhibition - presence of enzyme a shuts down synthesis of more enzyme a by inhibiting activity cells can regulate the expression of the genes encoding the enzymes Operons: The Basic Concept

ap_bio_chap_15_gene_regulation.ppt

Subject: 
Rating: 
0
No votes yet

0 15 Regulation of Gene Expression Overview: Differential Expression of Genes Prokaryotes and eukaryotes alter gene expression in response to their changing environment Multicellular eukaryotes also develop and maintain multiple cell types Gene expression is often regulated at the transcription stage, but control at other stages is important, too Concept 15.1: Bacteria often respond to environmental change by regulating transcription Natural selection has favored bacteria that produce only the gene products needed by the cell A cell can regulate the production of enzymes by feedback inhibition or by gene regulation Gene expression in bacteria is controlled by a mechanism described as the operon model Regulation of gene expression Precursor trpE gene (a) Regulation of enzyme

AP Biology Chapter 18 Notes Campbell/Reece

Subject: 
Rating: 
0
No votes yet

Chapter 18 Regulation of Gene Expression Conducting the Genetic Orchestra Cells precisely regulate their gene expression. Both prokaryotes and eukaryotes must alter thaier patterns of gene expression in response to changes in the environment. Remember, each cell contains the same genetic information, but the liver cell and brain cell express very different proteins, etc. This chapter will look at how cells (bacteria, eukayotes, etc.) regulate expression of their genes. Point: in eukaryotes, the expression of a gene is often regulated at the level of transcription. Learn this. Point: disruptions in gene regulation can lead to cancer 18.1 Bacteria often respond to environmental change by regulating Transcription

bio PS soln

Subject: 
Rating: 
0
No votes yet

Solutions to Practice Problems for Molecular Biology, Session 5: Gene Regulation and the Lac Operon ? ? Question 1 ? ? ? a) How does lactose (allolactose) promote transcription of LacZ? 1) Lactose binds to the polymerase and increases efficiency. 2) Lactose binds to a repressor protein, and alters its conformation to prevent it from binding to the DNA and interfering with the binding of RNA polymerase. 3) Lactose binds to an activator protein, which can then help the RNA polymerase bind to the promoter and begin transcription. 4) Lactose prevents premature termination of transcription by directly binding to and bending the DNA. Solution: 2) Lactose binds to a repressor protein, and alters its conformation to prevent it from binding to the DNA

bio PS

Subject: 
Rating: 
0
No votes yet

Practice Problems for Molecular Biology, Session 5: Gene Regulation and the Lac Operon ? ? Question 1 ? ? ? a) How does lactose (allolactose) promote transcription of LacZ? 1) Lactose binds to the polymerase and increases efficiency. 2) Lactose binds to a repressor protein, and alters its conformation to prevent it from binding to the DNA and interfering with the binding of RNA polymerase. 3) Lactose binds to an activator protein, which can then help the RNA polymerase bind to the promoter and begin transcription. 4) Lactose prevents premature termination of transcription by directly binding to and bending the DNA. b) What molecule is used to signal low glucose levels to the Lac operon regulatory system? 1) Cyclic AMP 2) Calcium 3) Lactose

bio diagram

Subject: 
Rating: 
0
No votes yet

glucose lactose operator (repressor binding site) PromoterZYA lacZ lacY lacAcrp lacI repressor active activator inactive PromoterIPromotercrp + - mRNA mRNA activator binding site polymerase RNA polymerase RNA operator (repressor binding site) PromoterZYA lacZ lacY lacAcrp lacI repressor active repressor lactose inactive activator inactive cAMP activator active PromoterIPromotercrp mRNA mRNA mRNA LacZ (?gal) LacY LacA activator binding site polymerase RNA polymerase RNA repressor active can metabolize lactose!cAMP + - + lactose + cAMP activator active polymerase RNA DNA DNA The lac operon: a model of gene regulation in E. coli MIT OpenCourseWare http://ocw.mit.edu 7.01SC Fundamentals of Biology Fall 2011
Subscribe to RSS - Operon

Need Help?

We hope your visit has been a productive one. If you're having any problems, or would like to give some feedback, we'd love to hear from you.

For general help, questions, and suggestions, try our dedicated support forums.

If you need to contact the Course-Notes.Org web experience team, please use our contact form.

Need Notes?

While we strive to provide the most comprehensive notes for as many high school textbooks as possible, there are certainly going to be some that we miss. Drop us a note and let us know which textbooks you need. Be sure to include which edition of the textbook you are using! If we see enough demand, we'll do whatever we can to get those notes up on the site for you!