Ans a) Tre A is an activator protein. When it is present, in the absence of glucose, cells actively transcribe the trehalose operon (trehalose only, normal cells). However, when environmental conditions are the same but Tre A is absent (trehalose only, lacking Tre A), transcription continues [because the repressor is unbound] but only at a low level—cells cannot be activated to transcribe the operon at a high level.
Ans b)Tre B is a repressor protein that, when absent, results in cells that have constitutive expression (i.e., “always on”) of the Trehalose operon , even in the absence of trehalose (glucose only).
Ans c) Since the data presented support that Tre B is a repressor protein, if a version of the protein were always bound to the A element of the promoter, transcription of the trehalose operon will be able to proceed—even in the presence of the carbohydrate.
3) Gene Control in Bacteria - Transcription Activators and Repressors You are interested in examining the...
Looking at the diagram of transcription in eukaryotes and using the information provided, how could the expression of lactase RNA be turned on and off by transcription factors, activators and repressors? Styles Font Paragraph Activators bind to genes at Rapressors bind to genes seauences and at shaoser sequences and The expression of RNA in eukaryotes is initiated by the binding of basal transcription factors to the promoter sequence of a gene. This leads to the recruitment of RNA polymerase to...
3. This is a schematic of a very simple pattern of gene expression. Yes means the protein is present and can bind the promoter. No means the protein is absent. Transcription factors are proteins that help regulate transcription by binding DNA Activators are transcription factors that help transcription. For example, they bend the promoter and make it accessible to RNA polymerase. Repressors are transcription factors that inhibit transcription. For example, they might bind the promoter and stop the RNA polymerase...
In eukaryotic cells, there are specific transcription factors (activators) that regulate gene expression. Describe the organization of eukaryotic genes (i.e. promoters/enhancers) and how transcription factors are able to control gene expression and enzyme activity. a) Throughout the course we discussed the enzyme lactase and how it is differently regulated (and therefore expressed) in different human populations. Describe how this gene is differently expressed in different populations and when this/these change(s) are predicted to have taken place. b) Differential gene expression...
8. (4pts) You are interested in the regulation of a gene that regulates cartilage production in joints, gene Crt. You find three proteins that regulate gene Crt expression. Protein A, B and C bind the promoter of the Crt gene to increase or decrease transcription of Crt. Proteins A and B both bind to site 1 but cannot bind to site 1 at the same time. Protein C binds to site 2 on the promoter. Transcriptional start site mRNA of...
Match each term associated with genes and control of gene expression with the appropriate description. A transcriptional unit" that consists of promoter multiple genes under the control of a single regulatory element. A transcriptional regulatory protein (prokaryotic or eukaryotic) which works by turning on or increasing gene transcription. activator The region of a gene to which RNA polymerase binds. Enhancer A transcriptional regulatory protein prokaryotic or eukaryotic) which works by turning off or decreasing gene transcription. repressor A molecule that...
The gene machine program shows you what happens when lactose is present in E. coli, and how the lac operon is under negative control. However, the lac operon is also under positive control from a protein called CRP, eAMP Receptor Protein. The absence of the lac repressor is essential but not sufficient for effective transcription of the lac operon. RNA polymerase also depends on the presence of CRP. Like the lac repressor, which can bind to the DNA and lactose....
Yet, all the cells in your body contain the same genes (and same alleles). The difference across cell types is that genes get selectively expressed (turned on or off) based on the proteins needed for cellular function given their environment. Select which statement explains the reason why hair does not normally grow on your muscle cells. a. Muscle cells have the gene for keratin, but do not express it b. Muscle cells do not have the gene for keratin and...
Draw a Eukaryotic Gene Schematic Draw features of importance at the DNA level Transcription start site +1 Promoter - as much detail as you can Gene start ATG and stop codons Transcription Regulatory Sequences such as activators/repressors and enhancers/insulators Draw features of importance at the pre-mRNA level Designate Introns and Exons Designate important Sequences to direct and regulate splicing three important sequences for the chemistry of splicing splicing regulatory sequences (ISS, ISE, ESE, ESS) Modifications at level of pre-mRNA UTRs,...
6. The gene for a hormone necessary for insect development contains binding sites for three transcription regulators called A, B, and C. Because the binding sites for A and B overlap, A and B cannot bind simultaneously. You make mutations in the binding sites for each of the proteins and measure hormone production in cells that contain equal amounts of the A, B, and C proteins. Figure 08-65 summarizes your results. For each of the following sentences, indicate if the...
need to know correct answers 26. B. Which of the following enzymes is associated with the repression of transcription? methyl transferase DNA polymerasex acetyl transferase histone kinase none of the above Section 2 - True/False (2 points each) 27. TFIIB regulates tissue or cell type-specific transcription 28._1 Eukaryotes have three different RNA polymerases that each can transcribe non-protein coding genes. 29. T The P site of the ribosome refers to peptidyl. be For T heoph UND 30._F_The input genetic material...