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Home > A Level > Biology > Biotechnology and Tissues Biotechnology and TissuesYou can download this essay for free. All you need to do is register and submit at least one of your essays to us. Or you can purchase this essay for just $2 instantly without registering
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| Words: 4208 | Submitted: 20-Nov-2011 This is what the first 3 pages of the essay look like    DescriptionIntroduction to Biotechnology and tissuesPreviewBiotechnologyIntroduction Biotechnology refers to technology used to manipulate DNA. The procedures are often referred to as genetic engineering. DNA is the genetic material of all living organisms and all organisms use the same genetic code. Genes from one kind of organism can be transcribed and translated when put into another kind of organism. For example, human and other genes are routinely put into bacteria in order to synthesize products for medical treatment and commercial use. Human insulin, human growth hormone, and vaccines are produced by bacteria. Recombinant DNA refers to DNA from two different sources. Individuals that receive genes from other species are transgenic. Viruses Viruses contain genetic material but are not living. Host cells are required for their reproduction. Structure Viruses are composed of an inner nucleic acid core (genetic material) and an outer protein coat (capsid). Viruses that infect animals have an outer envelope (membrane) that is derived from the cell membrane of the host cell may surround the capsid. The genetic material in some viruses is DNA; in others it is RNA. Reproduction When viral genetic material enters a cell, it is replicated, transcribed (mRNA is produced) and translated (proteins are produced from the mRNA) by the host cell. By this process, the host cell uses the genetic instructions in the virus to make more viruses. viral DNA ? mRNA ? protein If the viral genetic material is RNA, a DNA copy must first be made before transcription and translation can occur. The DNA copy of the viral RNA is called cDNA. viral RNA ? cDNA ? mRNA ? protein Bacteriophages Bacteriophages are viruses that infect bacteria. They are not surrounded by a membrane as the animal-infecting viruses discussed above. The virus attaches to the bacteria cell, a viral enzyme digests away a part of the wall and its DNA enters the host cell. Inside the host cell, the viral DNA is transcribed, translated, and replicated. Translation produces protein coats and the enzymes needed in the construction of new virus particles. The viral DNA is replicated. The protein coats and DNA are assembled into new viral particles. The host cell wall to ruptures releasing the newly formed viruses. Upon entering the cell, the viral DNA may instead, become integrated into the bacterial DNA. It is replicated along with the host DNA when the host reproduces. Eventually, it will become transcribed and translated as discussed above. DNA Animal Viruses Animal viruses usually do not kill the cell. The viruses have a membranous outer envelope with spikes. The virus enters the cell by endocytosis. Nucleic acid is released inside the cell. It is transcribed and translated to produce more viral DNA, protein coats and spikes. The virus acquires its membrane when it is released from the cell by budding (exocytosis). The host cell is not necessarily killed. Click here for more details on viral reproduction in animal cells. Retroviruses The genetic material of retroviruses is RNA. The retrovirus carries an enzyme called reverse transcriptase, which is capable of creating ... Download this essay in full now!Just upload at one of your essays to our database and instantly download your selection! Registration takes secondsOr you can download this essay for $2 immediately without registeringComments and reviewsReviews are written by members who have downloaded the essay No comments yet. If you download the essay you can review it afterwards. |
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