Pre-Messenger Rna Synthesis

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.

The four bases found in DNA are adenine (abbreviated A), cytosine (C), guanine (G) and thymine (T). A fifth pyrimidine base, called uracil (U), usually takes the place of thymine in RNA and differs from thymine by lacking a methyl group on its ring.

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

On encountering a host cell, the retrovirus attaches itself to receptors on the surface of the host cell’s membrane. Once inside the cell, the capsid opens, releasing RNA and reverse transcriptase into the cell’s cytoplasm.

Each human being has something called DNA. DNA is described as genetics and an extremely long macromolecule that is the main component of chromosomes and is the material that transfers genetic characteristics in all life forms. DNA constructs of two nucleotide strands coiled around each other in a ladder like arrangement with the sidepieces composed of alternating phosphate and deoxyribose units and the rungs composed of the purine and pyrimidine bases adenine, guanine, cytosine, and thymine. Each chromosome consist of one continuous thread-like molecule of DNA coiled tightly around proteins and contains a portion of the 6,400,000,000 basepairs that make up your DNA.

The DNA contains four types base: A (adenine) and T (thymine), G (guanine) and C (cytosine). These four letters make up the genetic alphabet and they spell out the commands for every single cell and organ of the body and also determine all the characteristics of the person.

within it. This packing is now known to be based on minute particles of protein

Every living thing has it’s own genetic code, or DNA. DNA has a double helix structure and is made up of phosphates, sugars, carbons, nitrogen bases, hydrogen bonds, and phosphodiester bonds. The phosophodiester bonds in DNA are responsible for bonding the 3’ carbon

This is done by means of the aminoacyl attachment site (the site at which the amino acid is attached to the tRNA molecule). Each tRNA molecule, by means of their anticodons (a sequence of three exposed free bases complimentary to that of the codons on

DNA, Deoxyribonucleic Acid, is the basic structure for all life, it is the blueprint, the instruction manual, on how to build a living organism. DNA is made up of four nitrogen bases, adenine, thymine, cytosine, and guanine which are connected by sugar-phosphate bonds. Through a process called Protein Synthesis, the nitrogen bases are the code for the creation of amino acids. Essentially, DNA makes amino acids, amino acids make proteins, proteins make organisms. This process has been taking place for much longer than scientists have been able to document. Those scientists are called geneticists and their field is genetics.

DNA is a long curved structure, made up of pairs of four specific bases: adenine, guanine, cytosine, and thymine, is the repository of a code from which all of our cells are made. The code is made up of base pairs which look like the

All living organisms, from amoebas to humans, have a molecular code called DNA in their cells, which instruct the activities that keep the organism alive. DNA is made up of long, twisted strands of four molecular “letters” (A, T, G, and C), which pair up according to their complementary base pairs, and their order determines how proteins — the vital molecules that perform all the major tasks in our cells — are made. (Refer to Diagram 1 to help sum up the concept.)

Being single stranded means that the side with the bases are not paired to another strand. When it is making the proteins, protein synthesis, it will be easy to for the amino acids to attach. mRNA leaves the nucleus with the copied information and attaches to the ribosome in the cytoplasm. mRNA will wait for amino acids molecules to attach. If the mRNA was double stranded, it would take more time for the amino acids to attach.

Finally, all the nucleotides are joined to form a complete polynucleotide chain using DNA polymerase. The two new DNA molecules form double helices.

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