Question 2 A lac repressor turns OFF the expression of the lac genes by Obinding to the promoter. Obinding to the lac genes. Obinding to the operator. ODNA polymerase.
Added by John B.
Close
Step 1
Step 1: The lac repressor is a protein that binds to the operator region of the lac operon. Show more…
Show all steps
Your feedback will help us improve your experience
Adi S and 80 other Biology educators are ready to help you.
Ask a new question
Labs
Want to see this concept in action?
Explore this concept interactively to see how it behaves as you change inputs.
Key Concepts
Recommended Videos
When lac repressor binds the lac operator, the operon is off. How does such binding turn off transcription? The lac repressor protein is a DNA binding protein that only binds to its operator in the presence of lactose The lac repressor protein is an RNA binding protein that only binds to its operator in the absence of lactose The lac repressor stops RNA biding at the promoter site The lac repressor protein is a DNA binding protein that only binds to its operator in the absence of lactose Lac genes are actually constitutively expressed If you have a pure solution of trp repressor protein and a pure solution of trp operator sequences, will they form a complex? (Will they bind to each other?) Yes. In the absence of tryptophan, repressor is able to bind the trp operator No. In the absence of tryptophan, repressor is able to bind the trp operator No. In the absence of tryptophan, repressor is unable to bind the trp operator Yes. In the absence of tryptophan, repressor is unable to bind the trp operator No answers are correct How is the bound lac repressor released when lactose is present? It depends on the concentration of other repressor proteins (for example the tryptophan repressor) Lactose triggers the release of hormones that stimulate metabolism Life requires repressors. When life wants to happen, repressors are activated Equilibrium between bound and unbound lactose and lac repressor Life requires inactive repressor proteins. When life wants to happen, repressors are deactivated In general, which genes are A) constitutively expressed and which genes are B) inducible? A) genes required for the biosynthesis of amino acids from scratch, B) glycolytic genes A) genes required for maltose (a sugar), B) genes that encode electron transport proteins A) genes required for the maintenance of cell wall material, B) genes required for the maintenance of fimbriae and flagella A) glycolytic genes, B) genes required for the biosynthesis of amino acids from scratch All answers are correct
Adi S.
Mystique T.
2.) How does the lactose repressor block transcription of the lactose operon? A. By binding to the operator DNA sequence B. By slowing the uptake of lactose into the cell C. By binding allosterically to the appropriate genes D. By "turning off" the appropriate genes in the intron
Sri K.
Recommended Textbooks
Biology for AP Courses
Objective Biology for NEET
Introduction to General, Organic and Biochemistry
Transcript
18,000,000+
Students on Numerade
Trusted by students at 8,000+ universities
Watch the video solution with this free unlock.
EMAIL
PASSWORD