Get Free Sample on Cell Biology And Chemistry Assignment

Question: Describe the movement of substances across the cell membrane by diffusion, osmosis, active transport and phagocytosis. Explain how the exchange of materials across the cell membrane is related to its structure. Use the concept of water potential to explain the movement of water between cells and their environment. Answer: Introduction The cell membrane, which is also called ctyoplasmic membrane or plasma membrane, acts as a barrier between the cell contents and the outside environment (Figueroa et al., 2013). The basic structure of a cell membrane is a bi-layer of phospholipid with protein molecules embedded in it. The phospholipid layers provide a good barrier between two aqueous compartments and the embedded proteins conducts some specific functions of cell membrane including transportation of molecules. This membrane is selectively permeable so that it can control what goes inside and comes out of the cell. A selectively permeable membrane is a type of membrane that allows some particular ions or molecules to go across it. The transportation of the molecules either can take place by active transport, which requires the expenditure of cell energy or by no expenditure of cellular energy that is passive transport (Stein, 2012). The cell membrane can also stop the passing of materials according to the condition of the cell or of the environment. Description of the processes The main processes involved in transportation across cell membrane are - Diffusion: It is a spontaneous process driven by the difference in a concentration gradient; that is the molecules of a fluid or gas moves from a higher to lower concentration region, and this process continues until the concentration becomes equal. Osmosis: Osmosis is another type of passive transport system which involves the movement of solvent molecules through a semi-permeable membrane. In this process no transportation of solute molecule takes place. The solvent moves from a diluted solution towards a concentrated one (Kotyk, 2012). It regulates the osmotic pressure of cell by maintaining the amount of water, and it depends on the concentration of dissolved particles inside and outside the cell. Active Transport: This process involves the movement of molecules across the membrane using chemical energy. It utilises ATP to force the molecules against its concentration gradient that is from lower to higher concentration. In this process, mainly large molecules like protein, large cells, and complex sugars are transported into and out of the cell. Figure: Active Transport Vs Passive Transport across cell membrane (Source: apocketmerlin.tumblr.com, 2016) Phagocytocys: It is a special type of endocytocys that takes up solids such as bacteria or nutrient by a cell. In the human body, it has an important role in the immune system and is mainly performed by white blood cells. Mechanism The mechanism of the above processes with respect to the cell membrane structure has been discussed below: Diffusion is a passive transport system that requires no cellular energy. In the case of lipid soluble particles diffusion occurs directly through the lipid bi-layer, but hydrophilic molecules cannot diffuse through the lipid bi layer. These molecules are diffused through protein channels present in the cell membrane (Figueroa et al., 2013). The protein molecule acts as a carrier, which automatically binds with the substrate and make it pass by exposing the substrate to the other surface of the membrane. This type of diffusion is also known as facilitated diffusion. The diffusion process is affected by size concentration and solubility of the molecules. Figure: Diffusion across cell membrane (Source: Classes.midlandstech.edu, 2016) As cell membrane is semi-permeable, transportation of molecules takes place by osmosis. Three conditions can happen depending on the concentration of any substance inside and outside the cell. If the solution is hypertonic that is higher than the cytoplasm, then water comes out of the cell and shrinkage of the cell occurs (Kotyk, 2012). When the solution has a lower concentration (hypotonic solution), water enters into the cell causing it to swell. If the concentration of the cytoplasm and the solution remains same, then it is called isotonic solution. In this condition, no movement of water occurs. Figure: Osmosis (Source: Instructables.com, 2016) Active transports are of two types: primary and secondary. In the first one, the trans-membrane protein molecules detect the substrates and transport it to the other side of the membrane utilising some chemical energy. In a secondary active transport system, the porous proteins form some channels across the membrane and molecules are forced inside by using electromagnetic gradient which is generated by lowering the concentration gradient of other substance (Kotyk, 2012). In fagocytocys process, first the cell recognizes the foreign matter and then is drawn towards it. Then it attaches its membrane to the bacterium by using a molecule present in it called surface receptor. The cell engulfs the bacterium along with cell membrane surrounding it and encloses it inside. Now the bacterium is digested by the enzymes released inside the cell, and it leaves a harmless residue which is either released out or utilised by the cell. Apart from these, other processes are also involved in exchange through a cell membrane, like endocytocys and exocytocys, which involves taking up and releasing specific substances respectively (Figueroa et al., 2013). Both of these are active transport processes. Effect of Water Potential Water potential is defined as the difference in potential energy between a given water sample and pure water at constant pressure and temperature. This is denoted by Greek letter . Here, water moves by osmosis from a higher water potential to where it is lower. This movement is affected by two-factor; those are pressure potential and solute concentration (Stein, 2012). With an increment in solute concentration, water potential decreases and with increased pressure exerted on the cell wall, the value of water potential increases proportionally. Depending on this factor the water potential changes and the transportation of water inside the cells occur accordingly. References: apocketmerlin.tumblr.com,. (2016).Exchange Across Plasma Membranes: Diffusion, Facilitated Diffusion, Osmosis and Active Transport. Retrieved 23 January 2016, from https://apocketmerlin.tumblr.com/post/15019772012/exchange-across-plasma-membranes-diffusion Classes.midlandstech.edu,. (2016).Cells: The Living Units. Retrieved 23 January 2016, from https://classes.midlandstech.edu/carterp/Courses/bio210/chap03/lecture1.htm Figueroa, X.F., Lillo, M.A., Gaete, P.S., Riquelme, M.A. Sez, J.C., (2013). Diffusion of nitric oxide across cell membranes of the vascular wall requires specific connexin-based channels.Neuropharmacology,75, pp.471-478. Instructables.com,. (2016).How to teach osmosis. Retrieved 23 January 2016, from https://www.instructables.com/id/How-to-teach-osmosis/ Kotyk, A., (2012).Cell membrane transport: principles and techniques. Springer Science Business Media. Stein, W., (2012).Transport and diffusion across cell membranes. Elsevier.

The Impact of Development Grants on Growth of Smes in Rural Tanzania Essay Example

The Impact of Development Grants on Growth of Smes in Rural Tanzania Essay Graduate Research Pre-Proposal Summery Statement of Intended Research Topic (CONCEPT PAPER) 1. Topic of Research: The suggested research topic is: The Impact of Development Grants on Growth of SMEs in Rural Tanzania. 2. Brief Statement of the Research Problem: Tanzania has recognised the importance of SMEs to the economic developments of the country, and has taken various measures to support their growth. However, despite of the efforts to enhance SMEs growth into the country, still a number of factors limit their growth. One of the many limiting factors is lack of capital to start up businesses by many potential entrepreneurs. This is coupled with the unwillingness of microfinance institutions (MFI) in the country to extend soft loans to rural entrepreneurs for various reasons. As a measure to ensure the rural entrepreneurs get capital to start up small businesses for income generation, the government in collaboration with other development agents have resorted to giving grants to rural communities so to start up small businesses and generate income. Various arguments have been put forward for and against this motive. There are those who support extending grants to business start ups arguing that it enhances growth of SMEs by providing capital to the needy which is otherwise could not be obtained. Others oppose the decision with arguments that grants do not support sustainable growth of SMEs but create dependence syndrome instead (Battle, P. (2007), Khan, M. (2008)). I therefore propose to conduct a study to find out the impact of grants on growth of SMEs in Tanzania, especially the rural areas where MFI credits are minimal or non-existent. I shall take the ongoing programme under TASAF as a case study. We will write a custom essay sample on The Impact of Development Grants on Growth of Smes in Rural Tanzania specifically for you for only $16.38 $13.9/page Order now We will write a custom essay sample on The Impact of Development Grants on Growth of Smes in Rural Tanzania specifically for you FOR ONLY $16.38 $13.9/page Hire Writer We will write a custom essay sample on The Impact of Development Grants on Growth of Smes in Rural Tanzania specifically for you FOR ONLY $16.38 $13.9/page Hire Writer Currently TASAF is giving grants to small groups of vulnerable individuals as capital to start up small businesses for income generation and growth. To what extent these grants support growth of the groups? Is sufficient number of groups grew up into sustainable business ventures? 3. Expected Achievements: This study will provide qualitative and quantitative information of the contribution of grants to the growth of SMEs in the country. The information is expected to be vital to policy making towards sustainable and enhanced growth of SMEs and entrepreneurship in the country. 4. Research methods to be used: It is planned that the study shall be carried out through a survey research. Various donors support individuals and groups to start up income generating activities by providing them with funds to finance business start ups. Such programmes include TASAF, SIDO, Compassion international (NGO) etc. These donors currently are running programmes that support individuals and groups interventions to start up and run income generating programmes. The beneficiaries are provided with cash grants that form initial capital to start up small businesses of their choice for the purpose to generate incomes for their subsistence and then development. A survey research with the use of supervised questionnaire is regarded to be the best method to collect data for the study. This method is regarded to be appropriate for the study because it will provide the respondents with guidance on providing answers to the questions and provide further elaborations on questions that may happen to be ambiguous to them. Also the method will facilitate the researcher to collect other qualitative data that otherwise will not be easy to collect.

Butternut

How to Collect Seeds and Plant Walnut / Butternut Now is the time to collect walnut and butternut seeds for planting this fall if you know how to identify them. Remember, after harvesting seeds, keep them moist for the entire time you store them - never let them dry out! They can also be planted the following spring. Husk or No Husk In theory, you can plant the seed with the husk. That is what nature does and seems to work okay. Still, you would be better served if you prepare the seed and husk or completely remove the hull. You can pour boiling water over the husks and let them soak overnight. Plant the soaked hull and seed the next day. Hulling Removing the husk increases the germination rate of walnut and butternut seeds but can become a big job if you have a large volume. There are mechanical hullers you can rent or purchase. The best way to de-hull small seed batches is to refrigerate in plastic bags for two or three weeks and until the husk turns black. The hull will wash off with a water hose under high pressure. Extended storage can drop the germination percentage if not done correctly so try to plant the seeds this fall (preferably the day after hulling). Preparing Seeds Most experts agree that the seeds will do just fine without scarification. Some say that the natural temperature cycle through the winter gives the seed the cold it needs but others recommend refrigeration for 3 months and planting in the spring (stratification). Planting Plant the nuts in an open area at a depth of one to two times their thickness. Mulching will help as you do not want the seed to freeze. Chicken wire over the planted seeds will deter digging rodents.

Having a Yen

Having a Yen Having a Yen Having a Yen By Maeve Maddox The word yen has described a Japanese monetary unit since the 1870s. This use of the word derives from Chinese yuan, round, round object, circle. In English the word yen can also mean desire or wish. Do You Have a Yen to Go to College? Have a yen for policy? Apply to be a Nat’l Academies graduate Fellow Have a yen to be an entrepreneur? Dive in now The American Yen for Zen This use of yen is from another Chinese word, Cantonese yan, craving. It came into the language as yin (1876) with the meaning intense craving for opium. The form yen dates from 1906 with the more generalized meaning sharp desire, hunger. Beginning as a slang word, yen probably gained a permanent place in the language because of its similarity to the verb to yearn, to desire earnestly; to experience a strong desire or longing for. In current usage, yen is often used to denote an idle desire rather than an intense craving. Want to improve your English in five minutes a day? Get a subscription and start receiving our writing tips and exercises daily! Keep learning! Browse the Vocabulary category, check our popular posts, or choose a related post below:Writing Prompts 101Rules for Capitalization in Titles25 Favorite Portmanteau Words

Reflection paper Article Example | Topics and Well Written Essays - 750 words

Reflection paper - Article Example In its pure form, which the author is quick to point out has not yet been discovered 'in nature', this form of authority rests on the individual's fitness to fulfill the legal obligations of the office he or she holds. This fitness is based on the person's specific training and demonstration of competence to carry out the duties of that office. Obedience is owed to that office and the legal elements it governs, but does not extend outside of this sphere in any way. The office itself is not a personal space for the individual filling it but is rather a space reserved for the carrying out of the legal duties of the position the person fills. Both in seeking redress and in issuing commands, the order of the established hierarchy is followed and each office within the hierarchy is filled with other individuals equally tested and deemed fit to fulfill the duties of that particular office. In theory, a hierarchy established on this pure form would run like clockwork, each individual acting within the boundaries of his or her office to which he or she is perfectly suited and trained and governed by clear laws of operation. Only the business of the office is conducted with little or no personal overlap of outside interests. To ensure all runs smoothly, there are set salaries for each of the positions within the hierarchy and all compensation is fulfilled in terms of money rather than 'in-kind' benefices. This is because benefices are difficult to quantify and often carry with them external, additional obligations. This type of authority, in an imperfect form, is found throughout the world almost every time you turn around. The republic of the United States is formed on such a system in which the President is elected to his office and appoints a number of supposedly qualified individuals to fill specific offices within his administration, each of which has their own set of obligations and responsibilities, their own hierarchical structure below them, and their own set o f laws to follow regarding how they conduct business. This is only an imperfect example, though, because it is not necessarily true that the electorate will vote for the most qualified candidate for President or that the elected President will place the most qualified candidates within the individual offices within his administration. Compensation for offices are frequently a mixture of salaries based on money and benefices consisting of favors, gifts, or other positive outcomes for the recipient. While behavior is ruled by law, there is often a great deal of politics occurring within this hierarchy, providing means by which laws are bent, broken, amended or over-ruled based upon a different system of obligation. Many of these same issues are also present in smaller organizations in which this form of authority is in place. These include corporations of all types as well as non-profit, philanthropic endeavors. Of course, in these smaller organizations, the rules can be bent to a gre ater or lesser degree simply because they are company policies rather than actual laws. In addition, the appointment of individuals to different offices can be based on things such as personal relationships or favors owed rather than actual fitness and training specific to the tasks of the office. In almost all systems of this sort, there is some reliance

The Pianist (2002) Movie Review Example | Topics and Well Written Essays - 1250 words

The Pianist (2002) - Movie Review Example In order to determine the film’s value, analysis will be focused on three of the film’s pivotal elements: directing, acting and music. It is through these elements wherein one will find that the film is a work of Polanski above all. It reflected his style, his genius, faults and failures and everything in between in his attempt to recreate the life and the sensibility of a martyred musician. The movie itself, its treatment of the story and the actor’s portrayal, presented the director’s interpretation of Wladyslaw’s experience in surviving the holocaust. Everytime he faced death, Szpilman survived because he was assimilated to the Polish society, he had friends, he had help, and he had his talents. The Jewish Police pushed him off the vehicle because he was a genius. Then the Nazi soldier towards the end of the film helped him live because he was talented. The case would have been otherwise, had the Pianist been an ordinary Jewish who is not assimilated in the Polish society. For instance, the set design for the film was entrusted to Allan Starski and Anna Sheppard, set design and costume designer, respectively. Both of them worked for Steven Spielberg’s opus, Schindler’s List, of the same theme: the Jewish experience under the Nazi atrocities. These two designers was able to reconstruct an era in their design that enabled the desired effect – the progression of horror in such peaceful city. The sequencing of streets, the film color tones, costumes, they highlighted the threats, the establishment of the ghetto, the indiscriminate killing, mass deportation and systematic extermination of Jews. With the help of these designers, Polanski was able to superbly recreate not only the period but the accuracy of the systematic deterioration of the Jewish plight in Poland during the Nazi occupation: from the building of the

Oliver Twist Essay Example for Free

Oliver Twist Essay Oliver Twist is the second novel written by Charles Dickens. It is all about Oliver who was an orphan living the world of crimes in London. The novel was published in Bentley’s Miscellany in a monthly basis. George Cruikshank was the illustrator of the said novel. Criticisms and opinions were gathered y Dickens as introducing the world of crimes. He exposed to the world the life of criminals and prostitutes. With this criticisms and comments, he took the opportunity of presenting a good view of his composition. He did not take the critics in a negative way. Among the works of Dickens, Oliver twist is the presented in a dramatic form. Oliver twist appears in series of novel in 10 theaters in London. The novel was also made with 25 numbers of versions since it started in 1906. The Famous Roman Polanski was the also made his own version of Oliver Twist. In the Oliver Twist, Oliver was an infant born in a workshop. After the adaptation of Oliver, he the came to an infant farm where he came o develop himself and then get back to the working place. Orphans were put to the workhouse to get their selves a home to get into. In the workplace, the orphans were experiencing the inhumane and mistreatment. With these mistreatments, the orphans were put into starvation. Oliver was asked to stand before his comrades to talk with their masters about the issue. Troublemaker is also named or recognized after Oliver. He does some job for other person who wishes to take him (Dickens, 2003). Oliver outside the workplace life was uneasy at first. He was so tired and hungry. He didn’t expect that life was also misery. Jack Dawkins is one of the persons who help Oliver by giving him a place to stay. Even though, he was recently together with thieves, he was still finds people who help him. As he stays with Dawkins, he also works with him. He came to the world of pick pocketers. With his work with Dawkins, he was also accused for some crimes. With the crimes being accused for him, he came to experience the world of criminals and prostitutes. He had himself put into a world where there are many negative insights. The life of Oliver really became a misery when he came with the criminals and do some criminal works. His life was also nearly put to death when he once put into criminal work when he was shot. With this misery life of Oliver he came to know about his family roots. He came to know who his brother is. He talks with Maylies and Doctor Losberne about his misery life. He had a brother who is a monk and he was claimed to be an inherited to a monk. Oliver was also an inheritor of an estate which his father wrote in will before his father died. And because of this they wanted to have the inheritance of Oliver. In the end, Oliver made a life of good after he had also got the inheritance. Oliver Twist is of the great novel of Dickens. The novel presented a story of humor and wit. The novel is of poverty mode and of cruelty. Oliver Twist may e given recognition for his thoughts about the world and its great creativity of story. With this Novel of Dickens, he used some world views. He relates the Novel with religion world view. He uses some facts with the monks when tackling about the religion. He discussed that eve though the family of Oliver was of different religions, they were still putting the peace on their heart. With respect to the political view, the politics in the novel represents some deficiencies of the true form of politics in the whole wide world. It was presented and explained on the novel how the politics is some sort of injustice. The real politics and politics in this novel are neither really similar nor different. In the geographical view, the novel was situated in way that the geographical mode is of the same way with the time of the novel was presented. It was situated in a community where people experienced difficulties with respect to community of criminals ad prostitutes. The people in the novel were creating a way that the geographic position of the community is essential. Tackling with the social view, the author speaks for the truth about the social community. It is explained in the novel that people need other people to survive in the community. People are born for other people. No man is an island. In order to survive the cruelty of the world, one person should have great communication and social interactions with other people. And last but not the least, about the economic view. One of the great topics in this novel is about the economic view. It is presented here that in life of poverty and scruelty; people were doing unnecessary things just to make their life into fulfillment. People may do some crimes and other illegal works just to survive in the low economized community. The use of providing great world issues in the Novel is a way to provide creativity with the said religion, political, economical, social and geographical ways. The author, Charles Dickens have very wide thought about the current issues I his time that he came to develop a novel with story that relates to the whole wide world. I is necessary for him that he even does not have good experiences in writing had no acclaimed awards for his works he still make it expressive for him to provide meaningful Novel. The Novel in particular was really fascinating for the story it provides is viewers or readers, it catches most of the reader’s attention. It does not need o make some more great speculations for the story to make it interesting. It was interesting in many ways. With its thoughts and ideas, it is still interesting. List of Reference Dickens, C. Oliver Twist. New York. Penguin Books; 2003.