Protein Synthesis in DNA Processes

Protein Synthesis in desoxyribonucleic acid ProcessesProtein entailment is the make for whereby desoxyribonucleic acid en commandments for the production of aminic group venereal diseases and proteins. It is a very multiplex and precise put to work and as proteins make up over half of the run dry mass of a cell, it is a vital exploit to the maintenance, growth and development of the cell. Proteins argon widely utilize in the cell for a variety of reasons and have many contrasting roles, for example some proteins come through structural support for cells while others act as enzymes which control cell metabolism.The formation of proteins takes place within the cytol, the portion of the cell located just outside the sum. Proteins are formed through condensation reactions which flummox amino acids together with peptide bonds in a particular sequence and the type of protein that is created is defined by the odd sequence of the amino acids. DNA and ribonucleic acid are nu cleic acids that are formed in the nucleotides and are two involved in the process of protein price reduction.Deoxyribonucleic acid, more comm just known as DNA, is located within the nucleus of the cell and contains the entire genetic regulation for an organism within its structure. DNA has two very of import functions which are to convey information from one generation of cells to the next by the process of DNA reappearance and to provide the information for the synthesis of proteins necessary for cellular function. Basically, DNA controls protein synthesis.The complex and precise process of protein synthesis begins within a gene, which is a distinct portion of a cells DNA. DNA is a nucleic acid which is make up of repeating monomers, called nucleotides, and in the case of DNA, these individual monomers consist of a pentose sugar, a phosphoric acid and quadruplet bases known as adenine, guanine, cytosine and thymine. DNA is a double stranded polymer, which has a misreprese nted ladder like structure, known as a double- lock. The double-helix of DNA is formed when two polynucleotide chains trades union together via base-conjugation between nucleotide units within the individual chains. The base pairs are joined together themselves by henry bonds and the pairings join in a very specific way, for example guanine will invariably only join with cytosine and adenine with always only join with thymine. The sequence of these base pairs on the DNA whit carries all the genetic information of the cell.Although the DNA does not produce the new proteins itself, it is creditworthy for controlling the process of protein synthesis. This is simply because DNA is far too big a structure to adios through the nucleus into the cytoplasm, so instead it sends a message to the protein making machine in the cytoplasm to start the process. It does this by sending this information via a chemical similar to DNA called ribonucleic acid (RNA). RNA is individual stranded pol ymer of nucleotides which is formed on the DNA. There are three types of RNA institute in cells, all of which are involved in process of protein synthesis. They are Messenger RNA ( template RNA), Ribosomal RNA (rRNA) and impartation RNA ( tRNA).Messenger RNA (mRNA) is a long, single stranded molecule which is formed into a helix on a single strand of DNA. It is manufactured in the nucleus and is a mirror imitation of the part of the DNA strand on which it is formed. The messenger RNA passes through the nucleus and enters the cytoplasm where is connects with the ribosomes and acts as a template for protein synthesis.Ribosomal RNA (rRNA) is a large, complex molecule which is make up of both single and double helices. rRNA is formed by the genes which are situated on the DNA and is found in the cytoplasm which, when bonded with proteins, makes up the ribosomes. The difference between DNA and RNA is that DNA is a double helix consisting of two strands whereas RNA is simply a singular strand, RNA also uses uracil instead of thymine and DNA consists of a deoxyribose sugar, whereas RNA consists of a ribose sugar.Transfer RNA (tRNA) is a very small, single stranded molecule that is manufactured by the DNA in the nucleus and is primarily responsible for the transfer of amino acids. These amino acids are found in the cytoplasm, at the ribosomes and operates as an intermediary molecule between the triplet figure of mRNA and the amino acid sequence of the polypeptide chain. It forms a clover-leaf shape, with one end of the chain ending in a cytosine-cytosine-adenine sequence (Toole, 1997). There are at least twenty contrastive types of tRNA, each transporting a different amino acid and at a central point along the chain in that location is a signifi squeeze outt sequence of three bases, called the anticodon. These are arranged along the appropriate codon on the mRNA during protein synthesis.All proteins are en commandmentd for in DNA, and the unit of DNA which codes for a protein is its gene. Since amino acids are regularly found within the proteins, it can thus be assumed that the amino acids must have their own code of bases on the DNA. This relationship between the bases and the amino acids is called the genetic code. There are just twenty amino acids that regularly occur in proteins and each must be coded for in the bases of the DNA. With the DNA only having four different bases present, if each were to code for a different amino acid, then only four different amino acids could be coded for. With there being twenty amino acids that occur regularly in proteins, only a code composed of three bases could satisfy the requirements for all twenty amino acids this is called the triplet code and this triplet code is more commonly known as a codon. Out of the 64 codons can be formed, three of these designate the termination of a message and these are called stop codons (UAA, UGA, UAG) and one codon (AUG) acts as the start signal for protein synth esis. The codon is a universal code, i.e. it is the same triplet code for the same amino acids in all living organisms. As there is more than one triplet code for most amino acids, it is called a degenerate code and each triplet must be read separately and must not over-lap. For example, CUGAGCUAG is read as CUG-AGC-UAG. (Toole, 1997)Protein synthesis is the process that is touch on with transfer of the information from the triplet code on the DNA to ensure the formation of the proteins. There are four stages in the formation of the proteins, these are synthesis of amino acids transcription amino acid activation and translation.The first stage, the synthesis of amino acids, is concerned with the formation of amino acids. The human body is qualified to synthesise amino acids, however it is not able to form the required amount therefore the remaining amino acids are supplied from the food that is ingested.The hour stage, transcription, is the process where a specific region of the DNA molecule that codes for a polypeptide is copied to form a strand of mRNA. Since the DNA is far too big a structure to pass through the membrane of the nucleus itself, the process of transcription takes place within the nucleus. Firstly, a section of the DNA separates as a result of hydrogen bonds between the bases being broken, causing the DNA to unwind into single strands. One strand functions as a template and the enzyme called RNA polymerase moves along the strand attaching RNA nucleotides one at a time to the new exposed strand on DNA. This mRNA sequence is known as the sense strand and the complementary DNA sequence which serves as the transcriptional template is known as the antisense strand. Using complimentary base pairing of nucleotides, the mRNA is an exact replica of the unused strand called the copy strand. The process of transcription continues until the polymerase reaches the stop codon and the in full formed mRNA moves out of the nuclear membrane, through the nu clear pores, to the ribosomes.The third stage, amino acid activation, is the process by which the amino acid combines with tRNA using energy from ATP. There are twenty different types of tRNA which bond with a specific amino acid and the amino acid is attached to the indigent end of the tRNA. The newly formed tRNA-amino acid begins to move toward the ribosomes in the cytoplasm.The fourth and final stage of protein synthesis occurs in the cytoplasm at the ribosomes, and is called translation. Translation is the means by which a specific sequence of amino acids is formed in accordance with the codons on the mRNA. Each mRNA molecule becomes attached to one or more ribosomes to form a structure called a polysome. When translation occurs, the complimentary anticodon of a tRNA-amino acid complex is attracted to the first codon on the mRNA and binds to the mRNA with hydrogen bonds between the complimentary base pairings. A second tRNA binds to the second codon of mRNA in the same way. The ribosome acts as a framework which holds the mRNA and tRNA amino acid complex together until the two amino acids are joined together by the formation of a peptide bond. As the ribosome moves along the mRNA each codon is recognised by a duplicate complementary tRNA which contributes its amino acid to the end of a new growing protein chain. This process continues until the ribosome reaches a stop codon, which then indicates that the polypeptide chain is finished and the polypeptide chain is then cast off. The formed polypeptides are then assembled into proteins and by this action, protein synthesis is complete.In conclusion, the DNA molecules contain a genetic code that determines which proteins are made in the body and these proteins include certain enzymes which control every biological reaction going on within the body. In simple terms, this is basically how life works.