DNA codes for protein production. DNA is located in the nucleus while the organelles responsible for protein production (ribosomes) are located in the cytosol. DNA is not able to leave the nucleus so a copy of the gene needed to produce the protein is made using mRNA. The mRNA leaves the nucleus, attaches to a ribosome, and determines which order the amino acids will be brought in by the tRNA to make that protein.
If you are asking why it does it, it is because that is just what the chemicals in DNA do. If you are asking why it is needed it is because if it didn't happen then the RNA wouldn't exist, and if the RNA did not exist then cells could not form amino acids, and if cells couldn't form amino acids then the cell could not create new structures, if it couldn't create new structures then it couldn't build its self or other cells and therefor life would not exist because shortly after the first cell had formed if the RNA had not been made the cell would have died.
The enzyme needed to make a DNA copy of RNA (including mRNA) is called reverse transcriptase. This enzyme is capable of synthesizing a complementary DNA strand from an RNA template, which is the first step in generating a cDNA (complementary DNA) library.
antisense mRNA
The process that produces mRNA is known as transcription. In this process a single DNA strand is used to make a copy of mRNA.
mRNA(messenger RNA)
Messenger RNA (mRNA) is a copy of the DNA message that is transcribed in the nucleus and can be translated into proteins in the cytoplasm. It carries the genetic information from the DNA to the ribosomes where protein synthesis occurs.
The enzyme needed to make a DNA copy of RNA (including mRNA) is called reverse transcriptase. This enzyme is capable of synthesizing a complementary DNA strand from an RNA template, which is the first step in generating a cDNA (complementary DNA) library.
antisense mRNA
The process that produces mRNA is known as transcription. In this process a single DNA strand is used to make a copy of mRNA.
mRNA does not copy DNA, intead, mRNA is copied FROM DNR. The process is call translation.
A traveling copy of DNA is called messenger RNA (mRNA). mRNA is synthesized in the process of transcription and carries the genetic information from the DNA in the cell nucleus to the ribosomes in the cytoplasm where it is used as a template for protein synthesis.
mRNA(messenger RNA)
DNA polymerase is the enzyme that "unzips" the complementary DNA strands allowing mRNA to transcribe, or copy, a section of DNA.
Messenger RNA (mRNA) is a copy of the DNA message that is transcribed in the nucleus and can be translated into proteins in the cytoplasm. It carries the genetic information from the DNA to the ribosomes where protein synthesis occurs.
mRNA makes a complimentary copy of the DNA molecule according to the base-pairing rule.
The process by which mRNA is created from a DNA template is known as transcription. After this has occurred, the DNA is still called DNA - it remains in the nucleus and has not been changed by this process. The copy of DNA is termed mRNA, or messenger RNA.
mRNA (messenger RNA) carries a copy of the DNA from the nucleus to the ribosomes.
The template strand is used to make a complementary copy. This is a type of DNA strand.