Biotechnology :: essays research papers

1. a)The Use of a Bacterial Plasmid to Clone and Sequence a forgiving GeneThe process begins with restriction endonucleases scanning and binding to double-stranded DNA at specific base-pair sequences, the recognition sites, in a predictable manner. The restriction sites argon normally 4 to 8 base pairs long and are characterized by the palindromic sequences, with both strands having the similar sequence when read in opposite direction. After the restriction endonuclease binds, it starts to disrupt, utilize hydrolysis, the phosphodiester bonds between neighbor nucleotides, causing the H-bonds between base pairs in the cutting region to be broken. This cuts the original double-stranded DNA strand, producing two DNA fragments, which may discord for different restriction endonucleases, depending on where the phosphodiester bond is broken when cut by the endonuclease. This process can produce either blunt ends (where ends of the DNA fragment are fully paired with no overhangs), or s ticky ends (where both DNA fragments have nucleotides lacking complementary bases and overhangs are produced). However, sticky ends are more effectual for genetic engineering. The next step, gel electrophoresis, separates the gene that has been excised, from the unwanted fragments taking advantage of chemical and physical properties of DNA. The DNA fragments travel through gel as a result of charge passed through it causing the longer fragments to separate from shorter ones, which helps in identifying gene and makes it easier to cut it out from the gel. The DNA fragment with the desired gene is, therefore, excised and purified. The same restriction endonuclease, that is used to cut the original DNA strand, then splices this gene into a plasmid (small, circular DNA molecules found in bacteria). Because the plasmid and the foreign gene are cut by the same restriction endonuclease, the sticky ends formed, are complementary and anneal to each other forming H-bonds. The DNA ligase refo rms the phosphodiester bonds, after which, the recombinant plasmid with the foreign DNA, is introduced into the bacterial cell, in the process of transformation, and replicates to form clones (exact copies of itself). Overall, this technique of altering sequence of DNA molecules became very useful for many reasons, one of which is production of hormones. Hormones much(prenominal) as insulin and somatropin, were produced by inserting a gene into a plasmid, and became essential hormones in medical practice. In this process, the needed human genes were incorporated into plasmids and activated or inactivated when needed, using specific inducers for promoter regions.

Essay on Dysfunctional Families in Song of Solomon -- Song Solomon ess

Dysfunctional Families in breed of Solomon The African American families in Toni Morrisons melodic phrase of Solomon present abnormality and dysfunction. Normalcy, seen in common nuclear families, is absent. The protagonist, Milkman, is shaped by his dysfunctional relationships with parental figures. The abnormality of the mother and child relationship is apparent in Song of Solomon. The mother figure seems to have misguided hopes. Toni Morrison, presents an image of an unnatural, extended time of maternal bonding. The character, condolence, breastfeeds her son, Milkman, until he is four or five years of age. Ruth breastfeeds Milkman for this unnaturally lengthy amount of time because it makes her feel like her son is a part of her. Breastfeeding him gives her immense pleasure and satisfaction. However, she hides her indulgence from the rest of the family until Freddie the janitor catches her. She knows it is wrong, but it makes her fooling life bearable. The children disp lay a mild amount of disrespect leading to severe denial of motherly compassion. We see this in a passage from Song of Solomon. He had never loved his mother, but had always known that she loved him. And that had always seemed right to him, the way it should be. Her confirmed, eternal love of him, love that he didnt flat have to earn or deserve, seemed to him natural(79). Milkman has a peculiar view of his mother. He did not think of his mother as a person, a separate individual, with a life apart from allowing or interfering with his own(75). Milkman does not think of his mother as an individual who needs his love or as a woman. To him it her job in life to love him. He sees her as a frail creature that needs protection f... ...is son has struck him. Yet, he feels pride in his son for standing up to him. Song of Solomon, joined by the dysfunction in the families, present an insightful image of the individual and the family of African Americans. Milkman, gained strength and endurance through the trials of abnormal, sometimes abusive upbringings. Each scar, whether it was mental or physical, was a lesson learned. Works Cited Byerman, Keith. Songs of the Ancestors Family in Song of Solomon. Approaches to Teaching the Novels of Toni Morrison. Ed. Nellie McKay. impertinently York MLA, 1997. Middleton, David. Toni Morrisons Fiction Contemporary Criticism. New York Garland, 1997. Morrison, Toni. Song of Solomon. New York The Penguin Group, 1977. Storhoff, Gary. Anaconda Love Parental Enmeshment in Toni Morrisons Song of Solomon. Style 31.2 (1997) 290-309.

The Old Man and the Sea Essay -- essays research papers

In The Old Man and the Sea, Ernest Hemingway describes an old fisherman and the unfortunate trials he faces as his "luck" runs out. Through the novel, the fisherman, Santiago, replicates Hemingways ideal man, a noble hero. Hemingway had a Code of Behavior that he himself followed. He had morals that were strict and an appreciation for thought and human nature. He had a specific way of living life and an understanding of time. He believed in taking risks and acting upon instinct. He believed that a someone who followed his Code of Behavior was a noble hero. In Hemingways Code of Behavior, a noble hero is a master blindsman. This means that he is not dependent on other people or on technology. It also means that he is a master at his art and he keeps practicing it in launch to better himself. The second characteristic of a noble hero is that he struggles in order to remain undefeated. This means that he does anything possible to reach his goal. He struggles and suffers in order to perfect his art and therefore, himself, "No consider what kind of suffering and trial he has to go Kapadia 2through he has to see his destiny"(Harada 270). The third characteristic of Hemingways noble hero is that he accepts defeat. Once he is defeated, once he can better himself no more, he should control trying because, "He lives in time. And the goal of time is death and destruction"(Harada 276). He should accept that he is no longer useful and that he has been defeated. These trey characteristics define Hemingways ideal man. In The Old Man and the Sea, Santiago exemplifies Hemingways Code of Behavior for a noble hero.In the novel, Santiago is a master craftsman. He is only dependent on himself. While the other fishermen use motor boats, Santiago uses his skiff. While the other men have many workers and helpers who hold some(prenominal) lines, Santiago has three lines all operated by his own hand. He is an expert, "the old man goes such(prenomin al) farther out than the other fishermen and casts bait in much deeper water"(Gurko 66). Because he knows the waters and the movements of the fish, he has a better chance of catching the fish. Although he is taking a greater risk by deprivation out deeper, he has a better chance of catching the bigger fish. Another thing that makes Santiago a master craftsman is his experience. He has bee... ... craft to the task Kapadia 5of playing the fish well"(Rovit 86). He knows tricks and occupies himself with bettering his ability to fish. He struggles and suffers in order to stay undefeated. He beats all odds and fights all battles with the thought that he can and will win. And so he does. He goes far out and acts on what he thinks is right. He does not reverence his actions nor does he regret them. He fights every battle as if it is his last and therefore comes out on top. Third, he accepts defeat. This is the most honorable characteristic. No matter how hard he has fought, once it is over, he does not look back wishing he could have acted differently. He accepts his mistakes and recognizes that, "He has overstepped the boundary of mans finite and extra nature"(Harada 275). He went out too far and this is what he gets. In these ways he is much like Hemingway, a noble hero. His actions and the consequences of them are easy notable and should not be look down upon. In the long run, Santiago answered his calling, fought his battles, and when he was finally defeated by his own pride, he recognize it and accepted it. This makes Santiago a noble hero.