BIOCHEMISTRY ASSIGNMENT 2 Example | Topics and Well Written Essays - 500 words

BIOCHEMISTRY 2 - Assignment Example The process involves either an addition of a transforming group to one of the amino acids of the polypeptide chain or its proteolytic cleavage. The modifications comprise glycosylation, phosphorylation, nitrosylation, ubiquitination, acetylation, methylation, proteolysis lipidation. The process of PTM is governed by enzymes such as transferases, kinases, ligases and phosphatises which act upon distinctive amino acid side chains or on the peptide linkages. The mechanism of action of these enzymes involves addition or removal of distinct functional groups, sugars, lipids, proteins etc. either from or to the amino acid side chains. 1. During the process of translation (e.g. disulfide bonding). Disulfide bonds are formed between the two sulphur molecules. Amino acid Cysteine contains sulphur, as a result disulfide bond is formed between two residues of cysteine (R-S-S-R). The bond formed is strong and plays an imperative role in accurate folding as well as stability of protein molecules. DNA is the basic genetic material which is made up of four nucleotides Adenine (A), Guanine (G), Cytosine (C) and Thiamine (T). Adenine always pair with Thiamine with a double Hydrogen bond while Guanine pairs with Cytosine with a triple Hydrogen bond. The process of transcription is responsible for the formation of messenger RNA or mRNA. This process takes place inside the nucleus in eukaryotes. The sequence of nucleotides in DNA is responsible for the amino acid sequence of mRNAs which are translated into proteins. Transcription and translation involves the processes such as initiation, elongation and termination. The process of transcription involves RNA polymerase which is attached to the promoter sequence. When the protein is desired, the gene is â€Å"switched on† and when protein is not required the gene is â€Å"switched off†. Elongation is carried out after the assembly of PIC at the promoter site, TFIIH is similar to helicase which unwinds the DNA. Terminatio n

An Analysis of the Importance of Setting In James Baldwins Giovannis Essay

An Analysis of the Importance of Setting In James Baldwins Giovannis Room - Essay Example The story itself is well written and intriguing, but many of the elements involved are only able to arise in the unique atmosphere of Paris. This paper will attempt to examine some of the reasons for Baldwin's choice of setting. The two American characters in the novel have both left the United States for different reasons. David, the narrator, claims that "I wanted to find myself" (p. 31) when leaving towards France, reflecting in hindsight that he would only find the self that he kept trying to escape. His past hinges on a dysfunctional relationship with his father, who spent most of David's youth drunk, to the point that by the time David grows older and the father attempts to get closer, then David no longer wishes it. David's rejection of his father stems from two root causes: firstly, David has begun to judge his father and, while not disapproving of the alcohol exactly, David resents his father's emotional absence through the years. Secondly, David has had at least one homosexual experience by this time - with a boy named Joey - whom he then promptly rejects. David's actions show a subconscious shame about his own homosexual tendencies, as well as a concern that his father might discover this aspect of his son. David's departure from the United States is an attempt to put physical distance between himself and his father, as well as psychological distance between himself, the experience with Joey, and the possibility of his father's discovery. Hella is on a similar journey of self-discovery with similar parallels of trying to escape. She is from Minneapolis and not much is said about her hometown. Instead, she is absent the first half of the novel because she is in Spain, contemplating David's marriage proposal. Hella's quest is to find a nobler purpose in her life than to become an average mother and housewife, yet when she returns to Paris, she grudgingly says that "it's really all I'm good for." (p.163). Her spirit is broken. Her old stance had been that a woman's attachment to a man was degrading, yet she now feels that even though a man will always be a stranger to a woman, she will only be free once she is committed to a relationship. She claims that "women get attached to something by default." (p.167), and that, essentially her purpose is therefore defined by David's need for her. Both of these characters go through an evolution in the course of the novel: they seek to escape their own nature, then accept it for a time and are happy, only to become miserable in the end by denying it once more. David only acknowledges his love for Giovanni when Giovanni is slated for execution; Hella leaves David when he needs the most support, primarily because of the revelation of David's love for Giovanni. Because of the very nature of the Americans, they are portrayed in sharp contrast to the Parisians. Hella declares that "coming back to Paris is always so lovely" (p. 160), implying the American romanticism attached to the city, but her true confusion of the Europe experience is hidden in her description of Spain "it's very beautiful. I just didn't know what I was doing there." David, while he enjoy Parisian life, identifies closely with the his fellow customers at the American Express Office, whom he perceives as having a quality "unedited, unrealized the sorrow of the disconnected." (p. 119). These aspects have become