cells22-Reg_gene_exp-2009

cells22-Reg_gene_exp-2009 - Bio 106 Cells Fall 2009...

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Unformatted text preview: Bio 106 Cells Fall 2009 Professor Owen 10/29/2009 Many Steps in Eucaryotic Protein Synthesis The concentration of a protein depends upon the regulation of each step. Even after a protein is translated, its activity can it be controlled by degradation, by binding, or by modification. 5. The Embryo Takes Shape gastrulation cells on the move turning genes on running time 07:47 http://www.pbs.org/wgbh/nova/miracle/program.html current topic ECB3 7-40 Autophagy What organelle is involved with degrading selected cellular contents (recycling center of the cell)? A. Golgi B. lysosome C. ER D. extracellular matrix E. cytoskeleton One way to degrade proteins: Cooper 8.44 The lysosome contain digestive enzymes (proteases). They take up cellular proteins and organelles, break them down, and reuse the components. The Proteosome ECB3 7-39 Why Does the Cell Regulate the Presence of a Protein? • Are there examples? • Is this important to us? thi Proteins can be targeted targeted for rapid breakdown by the attachment of ubiquitin molecules. Now the polyubiquinated protein will be recognized and degraded by the proteasome. Cells22-Regulation of Gene Expression 1 Bio 106 Cells Fall 2009 Professor Owen 10/29/2009 Which is an example of a cell process requiring regulated protein degradation? 11 What do you think! Is this relevant to your growth and development? A. cell division B. removing improperly folded proteins C. removing aggregated proteins D. answers A - C E. none of the above A. True B. False Cell Division – Cell Cycle Control Cell division: one cell divides into two. Cell cycle out of control is cancer! Controlled by ubiquitin Regulation of Gene Expression or Turning Genes On and Off and By How Much ECB2 18-1 Questions to Discuss • How are you different from the banana? • In what ways are you similar? • How much genetic information do you share with banana share with a banana ? … 10% … 50%? 10% 50%? … 100%? 100%? How much genetic information do you share with a banana? A. 10% B. 25% C. 50% D. 75% E. 99.9% Cells22-Regulation of Gene Expression 2 Bio 106 Cells Fall 2009 Professor Owen 10/29/2009 How Much DNA Do You Share With A Banana? Questions to Discuss • How are you different from the banana? – us: mobile, have brain – banana: a plant, fruit grown on a tree • In what ways are you similar to a banana? – skin, cells, genes, eukaryote, same amino acids, DNA & RNA bases • How much genetic information do you share … 10% … 50%? … 100%? NOVA-WGBH: Cracking The Code of Life (2001) Cracking Questions to Discuss How much genetic information do you share with a banana? • How are you different from the banana? – us: mobile, have brain – banana: a plant, fruit grown on a tree A. 10% B. 25% C. 50% D. 75% E. 99.9% • In what ways are you similar to a banana? – skin, cells, genes, eukaryote, same amino acids, DNA & RNA bases • How much genetic information do you share … 10% … 50%? … 100%? – 50% similar! – evolution did not have to reinvent more genes/proteins that it had to Regulation of Eucaryotic Gene Expression Differentiated Cells The main site of gene regulation is transcriptional control (step 1) ECB3 8-3 modified from ECB3 8-2 Cells22-Regulation of Gene Expression 3 Bio 106 Cells Fall 2009 Professor Owen 10/29/2009 DNA DNA is Copied into RNA RNA polymerase copies DNA into RNA. What is the likely function of this newly synthesized RNA? How is it regulated so that it only copies some genes in each type of cell? ECB2 7-9 A. translation B. transcription C. ligation D. snRNPs E. export from nucleus Review: Promoter Region TBP & Transcription Factors (TFs) TATA-binding protein (TBP TBP), proteins that bind the TBP, and transcription factors for RNA polymerase (TFIIs are needed TFIIs) for transcription of genes. for transcription of genes. These transcription factors are generally the same for all genes transcribed by RNA polymerase “general” (thus usually called “general” transcription factors). ECB3 7-12 The promoter region with TATA box is the site for RNA polymerase binding. The complementary strand serves as the template for transcription. ECB3 7-10 Gene Regulatory Proteins Identification of Regulatory Sequences Regulatory regions that control the expression of a gene can be examined experimentally. This is done by placing a regulatory region onto a “reporter gene” – a gene that makes a product that is easy to detect. ECB2 8-8 Cooper 7.18 Gene regulatory proteins control the transcription of genes. Cells22-Regulation of Gene Expression 4 Bio 106 Cells Fall 2009 Professor Owen 10/29/2009 Eukaryotic Promoter & Enhancer Action of Enhancers Without an enhancer, the gene is transcribed a a low basal level. Cooper 7.19 Addition of the enhancer stimulates transcription. The enhancer is active when upstream or downstream, close or far away! Cooper 7.21 Cooper 7.20 In addition to the promoter, efficient transcription requires a region called the enhancer. ECB3 8-10 Gene Regulation Occurs at a Distance (Eucaryotes) Cells22-Regulation of Gene Expression 5 ...
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This note was uploaded on 03/03/2011 for the course BIO 106 taught by Professor T.pageowen during the Spring '11 term at Conn College.

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