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The process of Protein Synthesis involves many parts of the cell. Unlike other similar productions, this process is very complex and precise and therefore must be done in proper sequence to work effectively. The slightest error during this process could cause the action to experience difficulty or even fail. For example, in the production of starch, glucose molecules are combined to be stored and eventually utilized as usable chemical energy. The cell can break down the starch with little difficulty as if each molecule was identical, although there is a wide variety of molecules. This is a different case in Protein Synthesis. In Protein Synthesis, there are twenty different amino acids and if one is out of place than is will effect the specificity of the protein. In a healthy person, the protein hemoglobin can be found in red blood cells, hemoglobin is helps with the transfer of respiratory gases from the blood to the tissues of the body. With an illness called sickle-cell anemia, the red blood cells are changed from a round, disk shape to a floppy looking sickle shape. These cells therefore cannot pass through small blood vessels due to their divergent shape. The actual cause of this mutation is a gene disorder, where the sixth codon of the protein glutamaric acid is changed with valine. This small change in the genetic code can cause severe defects in the effected such as blood clots, severe disorders and even death. All this can result from a misinterpretation in one codon in a chain of hundreds. Protein synthesis acts in this way; that is, if there is only the most minuscule mistake it can have monstrous effects.
Protein synthesis first begins in a gene. A gene is a section of chromosome compound of deoxyribonucleic acid or DNA. Each DNA strand is composed of phosphate, the five-carbon sugar deoxyribose and nitrogenous bases or nucleotides. There are four types of nitrogenous bases in DNA. They are Adenine, Guanine, Thymine, Cytosine and they must be paired very specifically. Only Adenine with Thymine (A-T) and Guanine with Cytosine (G-C).
Genetic information would be rendered useless if the stored information did not have a way of reaching the desired focal area. Since protein synthesis occurs in the cytoplasm and the DNA must remain in the nucleus, a way of transporting the code is essential. This comes in the form of messenger ribonucleic acid or m-RNA. Since the information on the DNA must stay the same on the m-RNA, the two have to be very similar. There are three major differences between RNA and DNA. RNA is only a single strand. The five-carbon sugar of RNA is ribose opposed to deoxyribose and in RNA the pyrimidine uracil replaces DNA\'s pyrimidine thymine. Since RNA is produced from DNA, the nucleotides of RNA can hold the same information as the nucleotides of DNA because the code for amino acids is centered around the RNA structure.
The process in which m-RNA is synthesized is called transcription. This process is similar to DNA replication in the way that for transcription to occur, the double helix DNA must be unwound as in DNA replication. The major difference between transcription and replication is that in transcription only one of the strands is used as a template and only one m-RNA strand is produced. Transcription can be broken up into three parts in order to be understood. These steps are initiation, elongation and termination. Initiation of transcription is how the transcription begins. The enzyme responsible for m-RNA synthesis is called RNA polymerase 2. The RNA polymerase knows where to begin transcription because it is coded into the DNA. Termination of transcription represents how the process stops. Transcription is stopped by certain sequences coded into the DNA template. These sequences are called terminators. At the terminator sequence, RNA polymerase 2 stops or pauses, causing the transcription to be completed and the m-RNA to be released.
DNA can replicate prior to mitotic division. This process is called semiconservative, meaning that each daughter duplex contains one parental and a complimentary replicated chain. For DNA to replicate, it must first be unwound. An enzyme called helicase, using ATP as an energy source does this. The helicase helps this in process by breaking the weak hydrogen bonds between nitrogenous bases. While
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Biology, Biochemistry, Molecular biology, Gene expression, Genetics, Protein biosynthesis, RNA, Translation, Genetic code, DNA, Transcription, Nucleic acid
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