, The genetic code is a set of rules that a cell uses to interpret the nucleotide sequence within a molecule of mRNA. This sequence is broken into three-nucleotide codon units (all things are triune with binary interactives). A ribosome is an intercellular structure made up of RNA and protein. It is the site of protein synthesis in the cell. It decodes the messages and forms peptide bonds. Ribosomes are where translation takes place. This means that ribosomes are the sites at which the genetic code is read by a cell. Ribosomes are composed of a complex of proteins and specialized RNA molecules called ribosomal RNA (rRNA).
TRANSCRIPTION TO TRANSLATION. The cell must first transfer information from DNA to mRNA to manufacture protein molecules through transcription. The translation process uses this mRNA as a template for protein assembly. This flow of information from DNA to RNA and finally to protein is the foundation of genetics. This is the starting point for understanding the function of the genetic information in DNA. Initiation occurs when the enzyme RNA polymerase binds to a region of a gene called the promoter. This signals the DNA to unwind so the enzyme can read the bases in one of the DNA strands. The enzyme is now ready to make a strand of mRNA with a complementary sequence of bases. The installed creation software program accomplishes this task, not a random natural selection process. Transcription is the process by which DNA is copied (transcribed) to mRNA, which carries the information needed for protein synthesis. Transcription takes place in two broad steps. First, pre-messenger RNA is formed, with the involvement of RNA polymerase enzymes.
The first step is transcription, in which the sequence of one gene is replicated in an RNA molecule.The second step is translation, in which the RNA molecule serves as a code for forming an amino-acid chain (a polypeptide). The information from DNA is passed on from one cell to another. Cell division is the mechanism by which DNA is passed from one generation of cells to the next. The parent organisms pass the information to their offspring. Although eukaryotes and prokaryotes both engage in cell division, they do so in different ways. The four steps of DNA transcription are initiation, promoter clearance, elongation, and termination.
There is no overlap in the genetic code. The four nucleotides found in mRNA, A, U, G, and C, can produce a total of 64 different combinations. Of these 64 codons, 61 represent amino acids, and the remaining three represent stop signals, which trigger the end of protein synthesis. Because there are only 20 different amino acids but 64 possible codons, most amino acids are indicated by more than one codon. (however, each codon represents only one amino acid or stop codon.) This phenomenon is known as redundancy or degeneracy, and it is essential to the genetic code because it minimizes the harmful effects that incorrectly placed nucleotides can have.
Redundancy in the genetic code means that most amino acids are specified by more than one mRNA codon. During translation, ribosomes move along an mRNA strand. With the help of proteins called initiation factors, elongation factors, and release factors, they assemble the sequence of amino acids indicated by the mRNA, thereby forming a protein.
Once a protein is complete, it has a job to perform. Some proteins are enzymes that catalyze biochemical reactions. Other proteins play roles in DNA replication and transcription. Yet other proteins provide structural support for the cell, create channels through the cell membrane, or carry out one of many other crucial cellular support functions.
