Transcription factors are proteins that help turn specific genes “on” or “off” by binding to nearby DNA. Transcription factors that are activators boost a gene’s transcription. … Groups of transcription factor binding sites called enhancers and silencers can turn a gene on/off in specific parts of the body.
What are true values? what is true value in chemistry.


What are the 4 transcription factors?

The transcription factors Oct4, Sox2, Klf4 and Nanog act as triggers for the induction of somatic cells to pluripotent stem cells. Oct4, Sox2, Klf4 and Nanog are all essential in stem cells and play an important role in biological processes.

What is true transcription?

Transcription is the first step in gene expression, in which information from a gene is used to construct a functional product such as a protein. The goal of transcription is to make a RNA copy of a gene’s DNA sequence. … Eukaryotic transcripts need to go through some processing steps before translation into proteins.

What are examples of general transcription factors?

The general transcription factors (GTF) include the TATAA box binding protein (TBP), a number of TBP-associated factors, and the RNA polymerase II enzyme, which synthesize mRNA strands from the genetic information.

What are transcription factors quizlet?

Transcription Factors. The proteins that bind to DNA regulatory elements (promoter, enhancer) to activate or repress transcription.

How many transcription factors are there?

Approximately 1,500 transcription factors (TFs) are encoded in the mammalian genome1 and constitute the second largest gene family, with the immunoglobulin superfamily being the largest.

What are transcription factors made of?

Transcription factors are modular in structure and contain the following domains: DNA-binding domain (DBD), which attaches to specific sequences of DNA (enhancer or promoter. Necessary component for all vectors. Used to drive transcription of the vector’s transgene promoter sequences) adjacent to regulated genes.

Which is true of bacterial plasmids?

A plasmid is a small, circular, double-stranded DNA molecule that is distinct from a cell’s chromosomal DNA. Plasmids naturally exist in bacterial cells, and they also occur in some eukaryotes. Often, the genes carried in plasmids provide bacteria with genetic advantages, such as antibiotic resistance.

What is true about DNA and RNA?

Correct answer: DNA and RNA share many characteristics. They are both composed of nucleotide monomers and are read in the 5′-to-3′ direction. They also share the same complementary base pairs, except RNA uses uracil in place of thymine; both contain adenine.

What is true of eukaryotic DNA?

Eukaryotic DNA is linear, compacted into chromosomes by histones, and has telomeres at each end to protect from deterioration. Prokaryotes contain circular DNA in addition to smaller, transferable DNA plasmids. Eukaryotic cells contain mitochondrial DNA in addition to nuclear DNA.

How do you identify transcription factors?

DNA BINDING ASSAYS USED TO STUDY TRANSCRIPTION FACTORS. The principal strategy in identifying and characterizing transcription factors is based on their ability to recognize and interact with specific DNA sequences present in the promoters of eukaryotic genes.

What are transcription factors How do they affect transcription?

Transcription factors are proteins that help turn specific genes “on” or “off” by binding to nearby DNA. Transcription factors that are activators boost a gene’s transcription. Repressors decrease transcription.

What is a transcription factor and how do they work?

Transcription factors are proteins possessing domains that bind to the DNA of promoter or enhancer regions of specific genes. They also possess a domain that interacts with RNA polymerase II or other transcription factors and consequently regulates the amount of messenger RNA (mRNA) produced by the gene.

Which of these is true of the cytoplasm of an unfertilized egg see Concept 18.4 page?

Which of these is true of the cytoplasm of an unfertilized egg? It is an unevenly distributed mixture of mRNA, proteins, organelles, and other substances. … Different genes are expressed so that different proteins are produced.

Which statement about pattern formation in an embryo is true?

This statement is true; the gene is transcribed in the mother, and the mRNA is delivered to the zygote. Pattern formation is the process by which the location of an embryo’s body segments is determined. Where is bicoid mRNA translated? bicoid mRNA is translated at the anterior pole of the fertilized egg.

What does epigenetics mean literally?

= Epigenetics is an emerging field of science that studies heritable changes caused by the activation and deactivation of genes without any change in the underlying DNA sequence of the organism. The word epigenetics is of Greek origin and literally means over and above (epi) the genome.

How do transcription factors get into the nucleus?

Most transcription factors are located in the cytoplasm. After receiving a signal from the cell membrane signal transduction, transcription factors are activated and then translocated from the cytoplasm into the nucleus where they interact with the corresponding DNA frame (cis-acting elements).

Are activator proteins transcription factors?

A transcriptional activator is a protein (transcription factor) that increases transcription of a gene or set of genes. Activators are considered to have positive control over gene expression, as they function to promote gene transcription and, in some cases, are required for the transcription of genes to occur.

How do transcription factors find their targets?

Transcription factors (which are described in the video) have to be able to first scan the genome so they can find their target sites and then bind there, which will turn genes on or off. It’s known that they can also randomly attach to the genome non-specifically.

What is the transcription factor in lac operon?

In this case, the combinatorial control is implemented molecularly by two transcription factors, the Lac repressor (LacR), which represses transcription and the cAMP receptor protein (CRP) which activates transcription. Activation by CRP requires the inducer cAMP, which is used by E.

What are the factors that affect gene transcription?

Various factors, including genetic makeup, exposure to harmful substances, other environmental influences, and age, can affect expressivity. Both penetrance and expressivity can vary: People with the gene may or may not have the trait and, in people with the trait, how the trait is expressed can vary.

Which is true about bacterial RNA polymerase?

Which is true about prokaryotic (bacterial) RNA polymerase? It is used during transcription. It does not require a primer. It has a detachable subunit, sigma factor, which recognizes the promoter.

How does a cell ensure accurate DNA replication?

The cell has multiple mechanisms to ensure the accuracy of DNA replication. The first mechanism is the use of a faithful polymerase enzyme that can accurately copy long stretches of DNA. The second mechanism would be for the polymerase to catch its own mistakes and correct them.

Are all bacteria competent for transformation?

During electroporation, the salts present in the preparation mix may lower transformation efficiency. Limit the volume of plasmid DNA to 1 µL per transformation. Column-purified DNA is most suitable as it is devoid of contaminants that interfere with transformation.

What is true for DNA but not for RNA?

RNA is very similar to DNA, but differs in a few important structural details: RNA is single stranded, while DNA is double stranded. Also, RNA nucleotides contain ribose sugars while DNA contains deoxyribose and RNA uses predominantly uracil instead of thymine present in DNA.

What is true about the sugar part in DNA and RNA?

The five-carbon sugar in DNA is called deoxyribose, while in RNA, the sugar is ribose. These two are very similar in structure, with just one difference: the second carbon of ribose bears a hydroxyl group, while the equivalent carbon of deoxyribose has a hydrogen instead.

Why DNA is more stable than RNA?

Due to its deoxyribose sugar, which contains one less oxygen-containing hydroxyl group, DNA is a more stable molecule than RNA, which is useful for a molecule which has the task of keeping genetic information safe.

Which statement is true about eukaryotic replication?

Prokaryotic DNA ReplicationEukaryotic DNA replicationOrigin of replication is about 100-200 or more nucleotides in lengthEach origin of replication is formed of about 150 nucleotides

Which of the following has true nucleus throughout its life?

Answer: Your Required Answer is Liver Cells.

What is not true about eukaryotic cells?

Eukaryotic cell wall is made up of cellulose hemicellulose, pectin chitin etc. Thus, is not true for eukaryotic cell. … In eukaryotes cell organelles are highly complex and membrane bound and the mitochondria in eukaryotes bear a separate circular DNA.

What is transcription factor enrichment analysis?

Transcription Factor Enrichment Analysis (TFEA) is a robust and reliable computational method that detects positional motif enrichment associated with changes in transcription observed in response to a perturbation.

What type of experiment S could be used to identify transcription factors involved in the regulation of this gene?

Several techniques can be used to examine transcription factor binding, including DNA footprinting and electrophoretic mobility shift assays (EMSAs), which are also known as gel shift assays. Both of these techniques are fundamental to the analysis of gene regulation.

What does acetylation do to histones?

Acetylation removes positive charges thereby reducing the affinity between histones and DNA. Thus, in most cases, histone acetylation enhances transcription while histone deacetylation represses transcription, but the reverse is seen as well (Reamon-Buettner and Borlak, 2007).

What are the general and specific transcription factors?

The General transcription factors are the factors which are used to form the pre-initiation complex during the process of transcription. The Specific transcription factors are either enhancers or repressors, which are specific DNA sequences that activate or repress the general transcription process.

How do transcription factors influence cell division?

How do transcription factors influence cell division? A. They directly transmit external signals to the cell’s nucleus. … Transcription factors regulate the expression of genes involved in cell division.

How are transcription factors regulated?

The activity of a transcription factor is often regulated by (de) phosphorylation, which may affect different functions, e.g. nuclear localization DNA binding and trans-activation. Ligand binding is another mode of transcription-factor activation. It is typical for the large super-family of nuclear hormone receptors.

What are three mechanisms by which transcription factors regulate eukaryotic gene expression?

Sets of transcription factor proteins bind to specific DNA sequences in or near a gene and promote or repress its transcription into an RNA. RNA processing. Splicing, capping, and addition of a poly-A tail to an RNA molecule can be regulated, and so can exit from the nucleus.

What is the function of lacZ gene?

The lacZ gene encodes the portion of the mRNA that is responsible for the production of β-galactosidase (B) and translation of the lacY gene produces the section of mRNA that is ultimately responsible for the production of an enzyme permease (P).

Under what conditions does the trp repressor block transcription of the trp operon group of answer choices?

The operator sequence is encoded between the promoter region and the first trp-coding gene. The trp operon is repressed when tryptophan levels are high by binding the repressor protein to the operator sequence via a corepressor which blocks RNA polymerase from transcribing the trp-related genes.

Which of the following conditions is most likely to cause the lactose operon to be transcribed group of answer choices?

Which of the following conditions is most likely to cause the lactose operon to be transcribed? The cAMP level is high and the lactose level is low. There is glucose but no lactose in the cell. The cyclic AMP and lactose levels are both high within the cell.