What would be the most likely effect of a mutation in a snoRNA that changed the antisense sequence?

What would be the most likely effect of a mutation in a snoRNA that changed the antisense sequence? The snoRNP would be assembled, but rRNA molecules would not be modified.

What is a promoter and how does it affect gene expression?

A promoter is a region of DNA where transcription of a gene is initiated. Promoters are a vital component of expression vectors because they control the binding of RNA polymerase to DNA. RNA polymerase transcribes DNA to mRNA which is ultimately translated into a functional protein.

How do mutations on the DNA level affect gene expression?

Changes to short stretches of nucleotides are called gene-level mutations, because these mutations affect the specific genes that provide instructions for various functional molecules, including proteins. Changes in these molecules can have an impact on any number of an organism’s physical characteristics.

What would be the consequence of a mutation in the gene that encodes sigma factor for bacterial transcription?

C. The RNA transcript may not be able to dissociate from the DNA template. What would be the consequence of a mutation in the gene that encodes sigma factor for bacterial transcription? The RNA transcript may not be able to dissociate from the DNA template.

What is a major disadvantage to a bacterial cell of having an operon?

What is a major disadvantage to a bacterial cell of having an operon? If there is a mutation in a regulatory region, none of the proteins will be synthesized.

Is an activator a transcription factor?

A transcriptional activator is a protein (transcription factor) that increases transcription of a gene or set of genes. Most activators are DNA-binding proteins that bind to enhancers or promoter-proximal elements. The DNA site bound by the activator is referred to as an “activator-binding site”.

Can a transcription factor be both an activator and a repressor?

The GA-binding Protein Can Serve as Both an Activator and Repressor of ribosomal protein Gene Transcription (∗)

What are the two types of transcription factors?

There are two mechanistic classes of transcription factors:

General transcription factors are involved in the formation of a preinitiation complex.
Upstream transcription factors are proteins that bind somewhere upstream of the initiation site to stimulate or repress transcription.

What do repressor and activator have in common?

Most eukaryotic repressors also are modular proteins. Similar to activators, they usually contain a single DNA- binding domain, one or a few repression domains, and can control transcription when they are bound at sites hundreds to thousands of base pairs from a start site.

How does a cell know which proteins should be destroyed?

The ones that are no longer needed or damaged. How does a cell know which proteins should be destroyed? Large protein complexes called proteasomes recognize the ones that have been tagged with the molecule ubiquitin.

What is an example of an activator?

One example of an activator is the protein CAP. In the presence of cAMP, CAP binds to the promoter and increases RNA polymerase activity. In the absence of cAMP, CAP does not bind to the promoter.

What does a repressor bind to?

A repressor is a protein that turns off the expression of one or more genes. The repressor protein works by binding to the gene’s promoter region, preventing the production of messenger RNA (mRNA).

Do repressors bind to silencers?

In molecular genetics, a repressor is a DNA- or RNA-binding protein that inhibits the expression of one or more genes by binding to the operator or associated silencers. A DNA-binding repressor blocks the attachment of RNA polymerase to the promoter, thus preventing transcription of the genes into messenger RNA.

Do repressors bind to enhancers?

Transcriptional repressors can bind to promoter or enhancer regions and block transcription. Like the transcriptional activators, repressors respond to external stimuli to prevent the binding of activating transcription factors.

Where does an activator bind to?

The activator protein binds to a specific sequence of DNA, in this case immediately upstream of (before) the promoter where RNA polymerase binds. When the activator binds, it helps the polymerase attach to the promoter (makes promoter binding more energetically favorable).

What activator means?

Definition of ‘activator’ 1. a thing or person that activates. 2. Chemistry. a substance used to induce or accelerate a chemical reaction.

What are enhancers and silencers?

CRMs that activate gene expression are typically referred to as enhancers, while those that repress gene expression are referred to as silencers. Transcriptional enhancers activate gene expression in a tissue-specific manner in development and also in adult cells in response to cellular or environmental stimuli.

Do activators bind to operators?

In general, activators bind to the promoter site, while repressors bind to operator regions. Repressors prevent transcription of a gene in response to an external stimulus, whereas activators increase the transcription of a gene in response to an external stimulus.

Why do eukaryotes not have operons?

When an operon is transcribed, all of the genes on the operon are on the same mRNA. Operons occur in prokaryotes, but not eukaryotes. In eukaryotes, each gene is made on individual mRNAs and each gene has its own promoter. Cells can’t afford to waste energy making genes if they don’t need them.

What does an inducer bind to?

Inducers bind to repressors, causing them to change shape and preventing them from binding to DNA. Therefore, they allow transcription, and thus gene expression, to take place.

What is the main function of a promoter?

A promoter is a sequence of DNA needed to turn a gene on or off. The process of transcription is initiated at the promoter. Usually found near the beginning of a gene, the promoter has a binding site for the enzyme used to make a messenger RNA (mRNA) molecule.

What does being a promoter mean?

Updated October 31, 2019. The main job of a music promoter, usually simply called a promoter, is to publicize a concert. Promoters are the people in charge of “putting on” the show. They work with agents – or in some cases, directly with the bands – and with clubs and concert venues to arrange for a show to take place.

What are the kinds of promoter?

Kinds of Promoters:

Professional Promoters: These are the persons who specialise in promotion of companies.
Occasional Promoters: These promoters take interest in floating some companies.
Financial Promoters: Some financial institutions of financiers may take up the promotion of a company.
Managing Agents as Promoters:

Which best describes a promoter?

Solution: The promoter is a nontranscribed region of a gene. The promoter is the regulatory region of a protein-coding gene at which RNA polymerase must bind to initiate transcription—it is not transcribed into the RNA.

What prevents Lac genes?

The lac repressor is a protein that represses (inhibits) transcription of the lac operon. It does this by binding to the operator, which partially overlaps with the promoter. When bound, the lac repressor gets in RNA polymerase’s way and keeps it from transcribing the operon.

Which best describes genetic mutations?

A) Genetic mutations that cause diseases are always passed on to offspring.	B) Some inherited genetic mutations can be good for the offspring.
C) Different genetic mutations cause few forms of cancer.	D) Somatic mutations can be inherited from parents or acquired during life.

What describes genetic mutations?

Alternative Titles: genetic mutation, mutagenesis. Mutation, an alteration in the genetic material (the genome) of a cell of a living organism or of a virus that is more or less permanent and that can be transmitted to the cell’s or the virus’s descendants.

Are mutations always bad quizlet?

Are all mutations harmful? No, some have no effect, some may be beneficial.