Exam 14: Gene Regulation

In Jacob and Monad's analysis of mutant E. coli strains in their study of the lac operon, the absence of the β-galactosidase enzyme, but presence of the lactose permease and galactosidase transacetylase enzymes, indicated that the mutation occurred in the _____ of the lac operon.

When the intracellular level of lactose drops, the repressor protein binds to the operator of the lac operon and shuts down translation of the lac structural genes. ​

Transcription factors that increase the rate of transcription by binding a target in the general transcriptional machinery and an enhancer are known specifically as:

A mutation in the IGF2 gene in pigs results in a threefold increase in the transcriptional activity of this gene in muscle cells; therefore, these pigs are leaner and more muscular. Because this mutation is in the noncoding region of the IGF2 gene, we can infer that:

Inducible genes are usually actively transcribed when:

The binding of active CAP to the lac operon promoter decreases the rate of transcription of the lac operon.

miRNA-protein complexes regulate gene expression by binding to a target mRNA and preventing translation.

Feedback inhibition is an example of:

How is enzyme activity regulated by feedback inhibition?

A new operon is discovered in bacteria. Transcription of the genes in this operon is blocked by the binding of a protein to DNA sequences upstream of the operon. This is an example of ____ control.

Figure 14-1 Refer to the accompanying figure. The area of the tryptophan operon labeled as 3 is the:

Translational controls of protein levels in bacteria are governed by the:

The function of upstream promoter elements in eukaryotes, such as enhancers and silencers, is to:

The rate of eukaryotic transcription after initiation is increased by:

Proteolytic processing, chemical modification, and protein degradation are all methods of posttranslational regulation mechanism.

Mutations in the TATA box increase the rate of transcription.

_____ is densely staining, highly compacted, and transcriptionally inactive region of chromatin.