Protein Replication

Transcription is the formation of an RNA strand from a DNA template within the nucleus of a cell. There are four nucleotides of DNA. These are adenine, cytosine, guanine and thymine. These nucleotides are transcribed to form messenger ribonucleic acid (mRNA) consisting of nucleotides made of adenine, cytosine, guanine and uracil. This transcription from DNA to mRNA happens by an RNA polymerase II. This newly created mRNA is read in the 5' to 3' direction in sets of 3. These sets are called codons. Each mRNA also has a cap and end. On the 5 prime side is a methylated guanine triphosphate and on the 3 prime is a poly A tail. Messenger RNA then moves to the cells cytoplasm and through the cells ribosomes for translation. Messenger RNA is matched to molecules of transfer RNA (tRNA) in the ribosomes to create amino acids. These amino acids subsequently form an amino acid chain. (Osuri, 2003) A visual representation of this can been viewed in figure 3.

3) As a ribosome moves along the mRNA, the genetic message is translated into a protein with a specific amino acid sequence.

After the DNA has been turned into mRNA a process called translation occurs and it turns the mRNA into tRNA.

Then the tRNA molecules link together and transfer the amino acid to the ribosome. An Anticodons pair with a codon takes the

Then the pre-initiation complex is form at the TATA box. Then uses cellular DNA-dependent RNA polymerase mediated transcription at the viral promoter site. During transcription mRNAs are capped and poly-adenylation by host enzymes. Then mRNAs are transported to the cytoplasm for translation into early proteins and migrate back to the nucleus, which mediates viral DNA replication4.

Ribosomes are the site of protein synthesis and are made up of two subunits. One of these units is large, and the other is small. These subunits consist of protein and ribosomal RNA. Ribosomes can be found floating free in a cell, or attached to the endoplasmic reticulum.

In translation, a mRNA, the messenger, is decoded and the information that comes from it. It is used to form chains of amino acid. The instructions of information that is used to build the amino acid chains are called codons. Codons are 3 nucleotides and there are a start and stop codons which signal the progress of the chains. The codons are read in order by tRNA, the transfer, each tRNA has an anticodon. The last thing that happens is the chains of amino acids are released into the cell when they reach a stop codon and they go do their own job in the cell.

Proteins and DNA are related because they interact with each other in such a way that DNA encodes protein. For example, DNA is made of a specific formation of nucleotides, which provides information about which amino acids should be synthesized to create proteins. Therefore, DNA and its composition play a vital role in the production of proteins, portraying a very significant relationship.

Although DNA contains the genetic code that is ultimately used to create proteins, DNA itself is not directly used in protein synthesis. To protect the DNA molecules, the cell uses an intermediate molecule called RNA that is directly involved in protein synthesis. That is, the DNA is first transcribed to form the RNA molecule, which then can be used in protein synthesis. We can imagine in a way that the genetic code in DNA is passed down to the RNA molecule. The advantage of using RNA is that the cell does not have to worry about damaging or mutating the DNA. In fact, because RNA is not passed down to offspring , our cells can easily recycle the damaged RNA molecule.

RNA processing is the process by which an RNA strand is modified, such that it is compatible for translation into a protein. RNA is synthesized from DNA during a process called transcription, a step in which an RNA copy of a DNA sequence is made. After the RNA strand is created, within the nucleus, the RNA is transferred into the cytoplasm of the cell where it can be translated into a genetic code that the cell can interpret and turn into proteins. The ribosomes of the cell are responsible for the synthesizing of the proteins from the RNA information. The process of protein synthesis is important to the central dogma of biology; the fact that DNA becomes RNA, which in turn

Transcription is where DNA is transcribed into RNA which then can be pass to the ribosome’s to act as a template for protein synthesis. Before transcription can begin DNA must unwind and the two halves of the molecule much come apart so exposing the base sequence. This process begins when a region of a two DNA strands is unzipped by enzyme called RNA polymerase attaches to the DNA molecule at the imitation site.

b) mRNA is a translation of DNA into a convertible protein substituting T with U. The template strand shown is the 1st step of transcription and it is transcribed to: GTA GAT TGG GGT CTC CTC. Each of the codons codes for a particular amino acid. For example, each codon is a triplet and codes for one amino acid. In the strand shown it separates it into triplets that will reveal codon and amino acid number. For example, CAT CTA ACC CCA GAG GAG = 6 amino acids.

The double spiral of DNA unwinds and unzips in such a way to release the instructions located for the given protein. Consequently, the instructions are carried out of the nucleus to the ribosomes. This point of location of the DNA molecule is called a gene. Genes act as a pattern for another type of nucleic acid called RNA. Instead of a thymine as in DNA, each adenine of the unzipped DNA attracts a uracil, U. The other bases follow the same pattern as in DNA i.e., G, T, and C attract the same partners C, A and G. The single chain of nucleotides which is newly formed is called messenger RNA and its formation is called as transcription. mRNA carries an exact duplicate of the information recorded in the DNA and leaves the nucleus with the instructions. The mRNA molecules are attracted to the ribosomes in the cytoplasm. Another smaller kind of RNA molecules called transfer RNA (tRNA.) also is there in the cytoplasm. Only one kind of amino acid can be attached to one end of a tRNA molecule while the other end carries a distinctive tag to identify it. The strand of mRNA lines up at the ribosome and the base pairs are attracted to their partners again. The attraction between the mRNA and the tRNA compliments each other. A triplet sequence of mRNA transcript codes for a specific amino acid and the sequence is called a codon. A corresponding triplet sequence on the transfer RNA (tRNA) called as

The formation of a protein begins in the genes, which contain the basic building information for all parts of living organisms. There are four DNA nucleotides that make up genes: A, T, C, and G. A codon is any arrangement of three of these nucleotides. Each triplet of nucleotides codes for one amino acid. First transcription will begin in the nucleus where mRNA will transcribe the DNA template. During both transcription and translation, there are three steps. The first step in transcription is initiation where RNA polymerase separates a DNA strand and binds RNA nucleotides to the DNA. RNA nucleotides are the same as DNA ones except that U replaces the T. The second is just the elongation of the mRNA. The third step of transcription is termination. This occurs when RNA polymerase reads a codon region and the mRNA separates from the

The last stage of the process, joining, involves bonding of complementary nucleotide to each other so as to form new strands. The nucleotides are joined to one another by hydrogen bonds to form a new DNA molecule. This joining continues until a new polynucleotide chain has been formed alongside the old one, forming a new double-helix molecule. This stage of the process also takes place with the assistance of enzymes. The DNA polymerase links the complementary nucleotides