Saturday, February 29, 2020

An Introduction To DNA

An Introduction To DNA DNA (deoxyribonucleic acid) is the genetic material of eve living organisms including some viruses. It is a dimer consists of two strands that immerse upon each other and appear as a double helix that are linked together covalently with each other. Each strand is made up of similar repeating units called nucleotides. Each nucleotide composed of three different moieties,a 2-deoxyribose sugar,a phosphate group and a nitrogenous base. 1.1.1 2-Deoxyribose sugar The 2-deoxyribose sugar, a major structural component of DNA is a cyclic molecule .The sugars are joined together by phosphate groups that form phosphodiester bonds between third and fifth carbon atoms of adjacent sugar rings.The 5†² carbon of deoxyribose sugar is attached to the 3†² carbon of the next, and make a network of 3†² carbon and 5†² carbon.5’end of a DNA molecule is characterized by a free phosphate (P) group and the 3†² end is characterized by a free hydroxyl (OH) group. It lacks an hyd roxyl group at the 2 position as in a ribose therefore a sugar moiety is a 2-deoxyribose. Two free hydroxyl groups are also located on the 5 carbon and 3-carbon of 2-deoxyribose sugar.These hydroxyl groups give a DNA oligomer its designation of 5 and the 3 end(usually accent as â€Å"three prime end† and â€Å"five prime end†). 1.1.2 Sugar-Phosphate backbone The 2-deoxyribose sugar and a phosphate group forms the backbone in the DNA which are highly polar and defines directionality of the molecule. The polar hydrophilic back- bone is surrounded by a core of hydrophobic bases and is important for the stability and structure of DNA. The phosphate groups have a negative charge that gives a concentra- tion of negative charge on the backbone of DNA and also makes DNA,a negatively charge 5 1 Fundamentals molecule. The charge is also neutralised by DNA-binding proteins that contain the pos- itively charged amino acids lysine and arginine, which are attracted to the negatively charged phosphate backbone. See Fig. 1.1. Figure 1.1: DNA backbone 1.1.3 Nucleic acid bases DNA contain four different nitrogenous bases that make monomer of one nucleotide different from other. These bases are adenine (A), thymine (T), cytosine (C), and gua- nine(G). The bases come in two categories pyrimidines and purines. Larger nucleic acids adenine and guanine are members of a class of doubly ringed structures called purines while the smaller nucleic acids cytosine and thymine are members of a class of singly- ringed chemical structures called pyrimidines .A six-membered ring with two-nitrogen molecule formed a pyrimidine structure whereas purine is produced by a nine-membered, ring with four- nitrogen molecule. Each unit of the ring constructing the base is numbered to for specific identification. They are arranged in a particular order along the backbone of DNA to make a long chain of varying sequence that contains the code for proteins.The sequence specifies the exact genet ic instructions required to create a particular organism with its own unique traits. 6 1 Fundamentals 1.1.4 Base Pairing in DNA The nitrogenous bases are responsible to form double-strand of DNA in consequence of weak hydrogen bonds and have specific shapes and hydrogen bond properties. The three hydrogen bonds form between guanine and cytosine and then denoted as G.C or C.G,depending on which is associated with the first strand. Similarly adenine and thymine also bond exclusively by pairing of two hydrogen bonds and then denoted as A.T or T.A. This coupling up of nitrogen bases termed as complementarity.,A hydrogen bond donor need an equivalent hydrogen bond acceptor to form a hydrogen bond in the base across from it. Purines are only complementary with pyrimidines because molecules in pyrimidine-pyrimidine pairings are very far from each other that doesn’t makes the hydrogen bonding to be established. Purine-purine pairing are energetically unfavourable because the molecule s are too close and create an electrostatic repulsion. The only possible pairings are GT and AC. Primary and secondary amine groups or hydroxyl groups are common hydrogen bond donar while carbonyl and tertiary amines are common hydrogen bond acceptor groups. There are two hydrogen bonds between an A:T base pair. One hydrogen bond lie between the 6†² primary amine of adenine and the 4†² carbonyl of thymine. The other hydrogen bond form between the 1†² tertiary amine of adenine and the 2†² secondary amine of thymine. On the other hand,G:C base pair has three hydrogen bonds. One hydrogen bond lie between guanine with its 6†² hydrogen bond accepting carbonyl and cytosine having 4†² hydrogen bond accepting primary amine. The second hydrogen bond also formed between guanine on 1†² secondary amine and cytosine 3†² tertiary amine and the third formed between the 2†² primary amine on guanine and the 2†² carbonyl on cytosine.

Thursday, February 13, 2020

Fashion retail concepts of the future Essay Example | Topics and Well Written Essays - 500 words - 1

Fashion retail concepts of the future - Essay Example The essay "Fashion retail concepts of the future" analyzes Fashion retail. In future fashion retail, there will be considerable use of online systems. A website legitimizes the existence of a business. E-commerce performs a physical role in enabling convenient access of products across distant areas. More fashion stores may face the pressure of opening their online versions to facilitate convenience of shopping among customers. In supply chain management, technology will be crucial in enabling efficiency. RFID technology helps track the movement of clothes in the distribution chain. This is possible though the use of tags that help track products from the manufacturing phase to the purchase stage. Fashion is ushering in an age of interactive shopping. Interactive experience means that a client takes charge of one’s shopping time. This involves the use of sensory simulation in testing products before purchase. For instance, the Burberry store in central London avoids the idea o f direct purchases. The store has simulated the website experience in its physical store on Regent Street. A customer, therefore, makes one’s purchases from the sofa while using a swipe machine. Clothing in the store has chips and identification technology that makes it possible for customer to witness images of clothes in catwalk. Mobile applications will be a key feature in fashion retail. Major brands such as SalesGossip, Burberry, Forever21, Shopstyle, and Tommy Hilfiger are investing in various applications.

Saturday, February 1, 2020

How the theory of Strategic Human Resource Management can assist Essay

How the theory of Strategic Human Resource Management can assist organisations in achieving and sustaining competitive advantage - Essay Example The paper tells that the increasing complexities and difficulties of management gave rise to the concept of managing at the strategic level. Managing at the strategic level is concerned with the long-term positioning of the organization. With the changes in the work environment, the private sector started recognizing that apart from financial and technological capital, human capital can also provide the competitive advantage. This led to innovation in HR practices or strategic human resources management. Delery and Doty defined strategic HRM practices as those that are â€Å"theoretically or empirically related to overall organizational performance†. Strategic Human Resources Management (SHRM) is about linking people with the organization – integrating HRM strategies into corporate strategies. In other words, SHRM aims to align or integrate decisions about people with the results that the organization aims to achieve. This is done because it is believed that integrating business strategy with HRM can lead to effective management of human resources and thereby enhanced organizational performance. The primary role of HR in the past has been compliance with laws, rules, and regulation. If the HR departments have a future-orientation and if the HR strategies operate as an integral part of the overall business plan, firms can achieve competitive advantage, according to Budhwar and Aryee. SHRM strategies can be used for knowledge creation, storage, and dissemination in organizations. HR practices influence an organization’s social climate which in turn leads to knowledge exchange and better organizational performance. Many researchers and scholars have contributed to strategic HRM with their own models and processes. For instance, Storey developed a model that demonstrates a shift from traditional personnel management to HRM. This model comprises of four key aspects – a constellation of beliefs and assumptions, strategic thrust informing d ecisions about people management, the involvement of line managers and shaping of employment relationship through commitment rather than forceful compliance. According to Storey, since the model has the linkage between employment policies and corporate plan, it can lead to competitive advantage. This model also identifies that strategic approach to HRM can be developed by bringing about changes in various elements of HRM functions such as recruitment and selection, training and development, and the conditions of employment. He suggested changes such as nurturing the workforce rather than monitoring them and management action should be based on the business need rather than following set procedures. Devolution to line managers has been proposed by many scholars as a core aspect of SHRM. SHRM has led to redefining the roles of the top management. Certain functions and issues are too complex for the top management to handle and devolvement of HRM to the line managers can lead to the fa ster response.