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Why can't DNA polymerase synthesize a new strand of DNA without the help of a RNA primer?
Wiki User
∙ 14y ago
Because DNA Polymerase requires the OH on the 3' as an active site. It uses the OH on the 3' end of a nucleotide to attach a phosphate from the 5' end of the next nucleotide. It only works in this direction, and that is why DNA polymerase works 5' to 3'.
Wiki User
∙ 16y ago
Wiki User
∙ 15y agoEnzymes, including DNA polymerase, are substrate-specific.
DNA polymerase III, the enzyme that extends a strand of DNA that is being synthesized along a template strand, has two distinctive requirements.
* First, it can only add a nucleotide to the 3' end of the new strand. This accords with the general observation that all nucleic acid synthesis (RNA and DNA) in biological systems proceeds in the 5' to 3' direction. * Second, it cannot initiate a new strand; it can only extend an existing double strand. A short double strand is formed in the cell by the enzyme primase, which forms a temporary DNA-RNA hybrid; in PCR (the polymerase chain reaction) a double strand is formed by a primer consisting of a short single-stranded segment of DNA produced in a laboratory. Both these requirements, like the details of specificity of other enzymes, result from the detailed arrangements of amino acids in the protein enzyme.
Wiki User
∙ 14y agobecause RNA primer must be recognize the DNA strand that should be transcribTed to anew strand then DNA polymerase attatch to RNA primer to add complementary nucleotides from the medium then ligase enzyme ligate nucleotides to form a complementary strand (anew DNA strand)
Wiki User
∙ 9y agoA new strand of DNA elongates only in the 5' to 3' direction because DNA polymerase can only add to the free 3' end. It contains the OH group needed for binding.
Wiki User
∙ 13y agoIt would be inefficient because it could not synthesize continuously it would have to always use Okazaki Fragments.
Wiki User
∙ 11y agoBecause DNApol needs a free 3' hydroxyl group to add its nucleotide too. Its active site isn't capable of initiating polymerization itself.
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What is a polymerase commonly used for?
Polymerase are best know for their role in DNA and RNA replication. The polymerase reads the DNA or RNA strand as a template to synthesize a new strand.
For DNA polymerase to link nucleotide together as new strands of DNA the first nucleotide must be attached to a because DNA polymerase can only add nucleotides to a pre-existing strand?
RNA Primer
Why RNA primers are needed during DNA replication and what is their fate?
DNA polymerase cannot begin the synthesis of new DNA.To synthesis a new strand of DNA ,RNA primer is required.The complementary RNA nucleotides,that are added opposite to the single strand of parent DNA are the RNA primer.
Why is RNA primase not DNA primase?
RNA primer is a short strand of RNA that is synthesized along single-stranded DNA during replication, initiating DNA polymerase-catalyzed synthesis of the complementary strand. RNA primase is the enzyme that synthesize the RNA primer.
What is the enzyme that uses one strand of DNA as a template to assemble nucleotides into a strand of RNA?
RNA Polymerase
What is a polymerase commonly used for?
Polymerase are best know for their role in DNA and RNA replication. The polymerase reads the DNA or RNA strand as a template to synthesize a new strand.
What is primer in pcr?
A primer (oligonucleotide of a specific sequence) is required for Taq polymerase to extend the template strand by adding complementary nucleotides. The function of the primer is to anneal to the template strand at a very specific site and facilitate the initiation of strand elongation mediated by Taqploymerase.
How does each separated strand begin a new strand?
With a small piece of primer,and active polymerase(enzyme) it replicates the complementary strand of the DNA
What is two major rules of DNA polymerase in the process of DNA replication?
One major rule of DNA polymerase is that it can only synthesize DNA in the 5' to 3' direction. This means that it adds nucleotides to the growing DNA strand by linking the 3' end of the incoming nucleotide with the 5' phosphate group of the previous nucleotide. Another rule is that DNA polymerase requires a primer, a short segment of RNA or DNA, to initiate DNA synthesis. The primer provides a starting point for DNA polymerase to begin adding nucleotides.
What does the first nucleotide attach to because DNA polymerase can only add nucleotides to a pre-existing strand?
An RNA primer.
For DNA polymerase to link nucleotide together as new strands of DNA the first nucleotide must be attached to a because DNA polymerase can only add nucleotides to a pre-existing strand?
RNA Primer
For DNA polymerase to link nucleotides together as new strands of DNA the first nucleotide must be attached to what because DNA polymerase can only add nucleotides to a pre exsisting strand?
RNA Primer
Why RNA primers are needed during DNA replication and what is their fate?
DNA polymerase cannot begin the synthesis of new DNA.To synthesis a new strand of DNA ,RNA primer is required.The complementary RNA nucleotides,that are added opposite to the single strand of parent DNA are the RNA primer.
Why is RNA primase not DNA primase?
RNA primer is a short strand of RNA that is synthesized along single-stranded DNA during replication, initiating DNA polymerase-catalyzed synthesis of the complementary strand. RNA primase is the enzyme that synthesize the RNA primer.
What is the enzyme that uses one strand of DNA as a template to assemble nucleotides into a strand of RNA?
RNA Polymerase
What enzyme is responsible for decodingthe DNA strand into an mRNA?
RNA Polymerase is the enzyme responsible for creating a strand of RNA.
Differences between DNA polymerase and RNA polymerase?
A polymerase is an enzyme that catalyzes the conversion of free nucleotides into a single strand. DNA polymerase differs from RNA polymerase in two major respects: * Like all enzymes, DNA polymerase is substrate-specific. DNA polymerase cannot extend a single strand of DNA; it needs at least a short segment of double-stranded DNA at the outset. * As its name implies, DNA polymerase incorporates deoxyribonucleotides into the new strand. RNA polymerase incorporates ribonucleotides. These differences mean that DNA polymerase is active when new DNA strands are formed, as in DNA replication, and RNA polymerase is active when new RNA is formed, as in transcription. Before DNA replication can begin, the two strands must uncoil, so that each can form a template for free nucleotides to attach to. But DNA polymerase cannot get started with a single strand! In vivo(in the cell) RNA polymerase, which is active in the presence of single-stranded DNA, catalyzes the incorporation of a handful of nucleotides into a new strand. The short length of double-stranded nucleic acid that is produced enables DNA polymerase to swing into action. This still leaves a potential difficulty: the nucleotides incorporated in the presence of RNA polymerase are the wrong sort (ribonucleotides). They are subsequently replaced by DNA polymerase. In vitro (during PCR, the polymerase chain reaction) a primer, specially synthesized in a laboratory, attaches to a specific segment of single-stranded DNA, and the DNA polymerase takes over from there. The primer consists of a short length of single-stranded DNA that uniquely complements a specific DNA segment that is targeted for amplification, for example for forensic analysis.In practice, there are several different DNA polymerases and RNA polymerases in an organism.
