What enzyme (protein) is responsible for performing transcription?
The enzyme is RNA polymerase and also non-enzyme transcription factors are needed.
The enzyme principally responsible for RNA synthesis in Escherichia coli?
the name of the enzyme is RNA polymerase and the process it performs is transcription. C is the correct answer all the other answers occur expect in different processes (translation and DNA synthesis).
Does transcription rate affect gene expression?
Expression levels of a gene is the amount of mRNA of that gene produced. Expression levels can increase either by 1) increasing the transcription rate or 2) increasing the time that the gene is expressed.Translation of the mRNA to protein can be increased by 1) increased numbers of mRNA, 2) increased numbers of ribosomes, or 3) decreasing the degradation of mRNA (which allows it to stay intact and be translated longer).There are several examples where increasing the transcription time of a developmental gene has huge changes in morphology. One of these is in the wrist bones of birds and bats:The length of the metacarpals is much longer in birds and bats than other mammals or reptiles. This is not due to a new gene, but an extension of the expression time of BMP-2 during embyronic development. In birds the expression time is about (if I remember correctly from a seminar I heard years ago) 8 hours longer than in humans.The mutation is in the transcription factor gene, of course. The transcription factor protein is responsible for binding to the promoter site to keep the gene turned on. A tighter binding means longer binding time = longer expression.Transcription itself is due to RNA polymerase enzyme:I have not seen (and cannot readily find) where mutations that either 1) increase the number of RNA polymerase molecules or 2) the rate at which they transcribe DNA to mRNA have affected evolution. As far as I can tell, RNA polymerase is optimized.
What are the enzymes involved in DNA transcription?
The Enzymes involved in eukaryotic transcription are :RNA polymerase I is located in the nucleolus, a specialized nuclear substructure in which ribosomal RNA (rRNA) is transcribed, processed, and assembled into ribosomes.RNA polymerase II is located in the nucleus and synthesizes all protein-coding nuclear pre-mRNAs.RNA polymerase III is also located in the nucleus. This polymerase transcribes a variety of structural RNAs that includes the 5S pre-rRNA, transfer pre-RNAs (pre-tRNAs), and small nuclear pre-RNAs.There are also many enzymes involved to execute Eukaryotic transcription as silencer, Enhancer, Repressor.There are many transcription factors are need to initiate eukaryotic transcription TFIID,TBP,TFIIA,TFIIA,TFIIE,TFIIF.Enzymes involved in prokaryotic DNA Transcription is RNA polymerase .
Difference between proteins and enzymes?
Enzymes are catalysts that help speed up reactions/metabolic processes. So if a protein plays a role as a catalyst, then it is an enzyme. If not, then it is not an enzyme. Other functions of proteins are membrane channels, signaling molecules, transcription factors, etc. Hope that cleared it up for you!
Where does transcription take place?
In eukaryotic organisms it takes place in the nucleus.
List several functions of proteins?
Enzymes - catalytic activity and function Transport Proteins - bind & carry ligands Storage Proteins - ovalbumin, gluten, casein, ferretin Contractile (Motor): can contract, change shape, elements of cytoskeleton (actin, myosin, tubulin) Structural (Support): collagen of tendons & cartilage, elastin of ligaments (tropoelastin),keratin of hair, feathers, & nails, fibroin of silk & webs Defensive (Protect): antibodies (IgG), fibrinogen & thrombin, snake venoms, bacterial toxins Regulatory (Signal): regulate metabolic processes, hormones, transcription factors & enhancers, growth factor proteins Receptors (detect stimuli): light & rhodopsin, membrane receptor proteins and acetylcholine or insulin.
What is the messenger RNA? Describe how it performs its function.?
The 1st link is an audio tutorial on the life cycle of m-RNA. It will help you visualize what's going on with m-RNA. m-RNA is all about the process of translation. How does the cell convert DNA into working proteins? The answer is m-RNA. he genes in DNA encode protein molecules, which are the "workhorses" of the cell, carrying out all the functions necessary for life. For example, enzymes, including those that metabolize nutrients and synthesize new cellular constituents, as well as DNA polymerases and other enzymes that make copies of DNA during cell division, are all proteins. In the simplest sense, expressing a gene means manufacturing its corresponding protein, and this multilayered process has two major steps. In the first step, the information in DNA is transferred to a messenger RNA (mRNA) molecule by way of a process called transcription. During transcription, the DNA of a gene serves as a template for complementary base-pairing, and an enzyme called RNA polymerase III catalyzes the formation of a pre-mRNA molecule, which is then processed to form mature mRNA (Figure 1). The resulting mRNA is a single-stranded copy of the gene, which next must be translated into a protein molecule. During translation, which is the second major step in gene expression, the mRNA is "read" according to the genetic code, which relates the DNA sequence to the amino acid sequence in proteins (Figure 2). Each group of three base pairs in mRNA constitutes a codon, and each codon specifies a particular amino acid (hence, it is a triplet code). The mRNA sequence is thus used as a template to assemble—in order—the chain of amino acids that form a protein. But where does translation take place within a cell? What individual substeps are a part of this process? And does translation differ between prokaryotes and eukaryotes? The answers to questions such as these reveal a great deal about the essential similarities between all species.
What enzymes are involved with DNA replication, and what are their roles?
Helicase:Unwinds ds DNA at the replication fork.DNA polymerase:Involved in synthesis of new DNA strand in 5' to 3' direction.Also performs proof reading and nick translation.Topoisomerase/Gyrase:Helps in relaxation of DNA from its coiled strcuture;relieves strainLiagase:Helps in annealing gapped strands(okazaki fragments)Primase:Provides a platform for DNA polymerase for synthesis of new strand.Telomerase:Adds length to the ends of DNA by adding repititive nucleotide sequences in the end.SSB and DNA clamp are accessory proteins not enzymes.