The lac operon - Study guides, Class notes & Summaries

the lac operon is expressed when glucose is low and lactose is high when in a complex with ____, the CAP protein binds to the CAP site and _____ the expression of lac operon. cAMP; switches on in the absence of lactose, the lac repressor is active and can bind to the operator which region associated with the lac operon is not involved in the binding of RNA polymerase? lacZ RNA polymerase binds to the promoter the most efficient control of eukaryotic gene expression is achieved at the level ...

CBE 235 Final Question and answers rated A+ 2023/2024 Lac Operon - correct answer -involved in heating lactose: inducible operon 1) The lactose repressor protein coded by Lacl bound to the operator tightly near the mRNA start site, blocking the ability of RNA poly to bind 2) Lactose introduced--> Lac repressor binds to lactose and changes conformation such that it can no longer bond to the operator 3) RNA poly can access the promoter and transcription goes 4) LacZ,LacY,LacA are transcribe...

What will be the effect on transcription when an inhibitor is in play? A. Allow transcription B. Prevent transcription - Answer-B Explanation: An inhibitor prevents activator from binding to DNA; activators are used in positive regulation (increasing transcription) - thus, the inhibitor prevents the activator from positive regulating (increasing) transcription. What will be the effect on transcription when an inducer is in play? A. Allow transcription B. Prevent transcription - Answer-A Ex...

What will be the effect on transcription when an inhibitor is in play? A. Allow transcription B. Prevent transcription - Answer-B Explanation: An inhibitor prevents activator from binding to DNA; activators are used in positive regulation (increasing transcription) - thus, the inhibitor prevents the activator from positive regulating (increasing) transcription. What will be the effect on transcription when an inducer is in play? A. Allow transcription B. Prevent transcription - Answer-A Ex...

What is the first mRNA processing step? - ANSWER 5' capping Different mRNAs are made from the same initial pre-mRNA by ________. - ANSWER alternative splicing RNA transcription begins at a ________. - ANSWER promoter ________ protect(s) the pre-mRNA molecule. - ANSWER the 3' poly-a tail The process of pre-mRNA splicing removes ________. - ANSWER introns Spliced ________ differ in their exons. - ANSWER mRNAs Identify the three phases of transcription. - ANSWER initiation, elongation, te...

BIO 1A03 Midterm 2 Questions and Answers Graded A Prokaryotic growth and cell division -nutrient-rich environment -favorable temperatures Housekeeping genes -genes required at all times for normal function -all ways transcribed and translated -allow constant maintance for general cellular activity -e.g. structural protein of a cell, DNA and RNA polymerase, genes coding for ribosomal proteins -constitutive Regulated genes genes that can be turned on and off at a needed basis Francois Jacob and...

Bio 101 Chapter 7 Exam Questions and Answers All Correct A change in a cell's DNA sequence is Select one: a. transcription. b. a mutation. c. an operon. d. translation. e. replication. - Answer-b. a mutation A diploid cell only has two copies of most genes, but can make hundreds of copies of a protein from those genes per second because Select one: a. while transcription can repeat and make multiple mRNA copies of genes, and multiple ribosomes can translate the same mRNA. b. mul...

The fundamental units of heredity are known as _____ and multiple versions of them are known as _____ . Correct Answer genes; alleles Which of the following best describes a typical prokaryote chromosome? Correct Answer circular, composed of DNA Genes with different information at the same locus are called: Correct Answer alleles What is typically the difference between the bacterial chromosome and a plasmid? Correct Answer The chromosome contains genes that are essential for survival, ...

FRNSC 420 - EXAM 4 PRACTICE QUESTIONS AND ANSWERS (100% PASS) positive allosteric regulation - Answer️️ -binding of a regulatory molecule to an enzyme induces a conformation change, increasing the enzyme's affinity for a substrate - proteins are activators = enhance RNAP binding and/or induce conformational change, can change binding constant (KB) or rate constant (kf), lowers activation energies negative allosteric regulation - Answer️️ -bound regulatory molecule must release ...

Coupled transcription and translation - Ribosomes bind mRNA while mRNA is still being created, so that translation begins while transcription is still occurring - Advantage of lacking a nucleus Translation initiation - - Initiation factors bind ribosome to the ribosome binding site known as the Shine Delgarno sequence (AGGAGG) - Begins at start codon 1. 30s subunit binds mRNA 2. IF2 interacts with initiator tRNA 3. fMet-tRNA binds to start codon 4. Association of initiator tRNA with ...