Osmosis: Concentration

OSMOSIS and TONICITY IN POTATO STRIPS The purpose of this experiment was to make observations and conclusions about the ability of cells to adjust to varying chemical concentrations in the environment and to observe the effect of isotonic, hypotonic and hypertonic solutions on cells. Hypothesis If a solution is Hypotonic, then water will move from the beaker into the potato because water outside the cell will be in higher concentration than water inside the cell. If a solution is Hypertonic, then the solution will move into the cell from the beaker and water will move out of the cell into the water because of a difference in concentration. If a solution is isotonic, then the cells will remain the same because the solution concentration is the same as in the cell. Materials Fresh potato, knife or scalpel, three test tubes, test tube rack, dropper pipette, paper towels, electronic balance, timer, three provided solutions labeled A, B, and C. Procedure Obtain three test tubes and a test tube rack. Label the test tubes A, B, C using a wax pencil. Cut three French fry type strips of potato 7cm in length, no thicker than 5mm. Pat each potato with a paper towel. Measure the initial mass of each strip and record it before putting each in a test tube. Use a dropper pipette to cover the potato strip in test tube A with solution A, the potato strip in test tube B with solution B, and the potato strip in tube C with solution C. Place the tubes in a test tube rack and wait one hour. Remove the strips from the test tubes after one hour and pat dry with a paper towel. Measure the final mass of each strip and record it. 10. Examine each potato strip and observe any changes in texture. Results In Solution A, the potato slice in the water did not change, indicating the solution contained an equal amount of concentration. In Solution B, the potato slice in the water is larger, indicating that more molecules went into the potato than came out, because there was a higher concentration of water outside the potato. The potato slice from Solution C is much smaller indicating that more water molecules came out of the potato than went in because there was a higher concentration of water inside the potato. Conclusion In conclusion, the hypothesis was found to be correct. Solution A was Isotonic because the final mass of the potato slice was 2. 9 as opposed to 2. 8 at initial mass, which basically stayed the same. Solution B was Hypotonic because the initial mass for the potato slice was 3. 3 then expanded and weighed 3. 6 at final mass. Solution C was Hypertonic because the potato slice lost water and became much smaller in which the initial mass was 2. 8 and the final mass weighed in at 2. 2. In all three solutions, water is moving across the membrane to establish equilibrium. Based on the Diffusion-Osmosis Review on page 26, and not knowing the definite solution in each tube I am going to conclude that there was Saline in Solution A 0. 9% Sodium Chloride which makes cells neutral. In Solution B, therewas a small percentage of salt predicting . 9%. In Solution C, salt was higher than . 9%. All had salt in the tubes but different tonicity. The water could go in or out of the potato to equalize the concentration of salt in the solution. Based on this experiment and using this in real life, it taught me that when mixing the intravenous fluid for a patient to make sure only 0. 9 percent of salt is added in order for the saline to be isotonic to the red blood cells. If not, the red blood cells will expand and complications will arise.

How global warming works Essay Example | Topics and Well Written Essays - 2000 words

How global warming works - Essay Example Global warming occurs because carbon monoxide and additional chemical emissions become trapped under the ozone layer; as a result, the temperature of the Earth steadily increases. The impact of global warming has been researched extensively, and in addition to the extinction of plant and animal species, the human race itself may one day become extinct. It has been suggested that global warming will have far-reaching consequences for all life on Earth. In observing the possible crash on the environment (the blend of all living and non-living basics in a specified area), the extinction of animals and plants as well as land formations are most important. It is thought that more than 120 species of amphibians have already vanished forever because of global warming. The Golden Toad, for example, which was once mostly found in Monteverde, Costa Rica, was one of the first amphibians to become extinct. This reptile was last seen in 1989. Animals are not the only living organism in danger of extinction-plants are also being harmed by the effects of global warming. Several plant species have been confirmed extinct because of radical changes in weather patterns in a number of areas (Abarbanel p57). The Fern Gully in Jamaica is an... Another example of the way in which global warming affects landscapes and ecosystems is the coral reef. These are important parts of the ecosystems in which they live-the death of a coral reef will in turn contribute to the eventual extinction of countless plant and animal species which live in it. The Pew Centre on Global Climate Change issued a report on February 13, 2004, stating that global warming might very well further contribute to the extinction of coral reefs. The report goes further to state that in areas with large geographic ranges and extremely high latitudes, certain coral species are very vulnerable to the effects of global warming, and that there is no doubt that coral species in these types of areas are affected. Plants and animals are not the only species which will experience the devastating effects of global warming. It is expected that the human race will be even more severely affected. Global warming will have far-reaching and destructive consequences, with famine in areas where the climate has been devastated to the extent that growing food is no longer possible, mass migration of people from significantly affected areas, and perhaps even war. Approximately two hundred million people may be affected if the sea-level rises significantly: Vietnam, Bangladesh, China, India, Thailand, Philippines, Indonesia and Egypt are on the top of the list. The consequences of a large increase in sea-level in such areas are likely to be severe: a dramatic change in climate, scarcity of resources in affected countries, and perhaps eventually mass migration of people out of affected countries, leading to scarcity of resources in the

Same sex marriage Essay Example | Topics and Well Written Essays - 750 words

Same sex marriage - Essay Example Compare and contrast: Both the same-sex marriage and traditional marriage support the concept of marriage, i.e. the contract between partners. To be specific, same-sex marriages never deny the scope of family in personal life. At the same time, family is the backbone of traditional marriages. One can see that the proponents of same-sex marriage consider that the concept of family can provide legal consent and acceptance in the society. David E. Newton states that, â€Å"The question raised by advocates of same-sex marriage is whether a state can constitutionally refuse to issue a marriage license to two individuals of the same sex† (62). Besides, those who accept same-sex marriage claim that all the rights that are enjoyed by the partners within traditional marriages must be allowed to the partners (say, same-sex). One can see that social recognition is important within the context of married life, and those who are in favor of same-sex marriage or traditional marriage are rea dy to accept the same without any argument. So, the supporters of same-sex marriage and traditional marriage are aware of the importance of family, legal consent, and social acceptance. One can see that most of the marriages (say, traditional) are related to religious belief, morality, and legal/ constitutional support. All the world religions support traditional form of marriage because the same is a contract based upon belief. Besides, the moral side of traditional marriage is related to certain limitations on individuals. At the same time, traditional marriages help to gain legal/constitutional support in the society. On the other side, the proponents of same-sex marriages consider the same as a deviation in sexual interest. They never accept the intrusion of religion into the context of marriage. Instead, they consider that religious belief and marriage are different and individuals must be allowed to lead lives according to their personal interest. If individuals are interested in same-sex marriages, they must be allowed to do so. Peter Strandby states that, â€Å"Finally, gay activists’ claims to full citizenship through equal access to marriage, is denied based on a religious set of beliefs, that homosexuality is morally wrong and that same-sex marriage would threaten existing individual liberties such as freedom of religion and expression† (21). Besides, the supporters of same-sex marriages declare that the society must show readiness to provide legal sanction to same-sex marriages. So, same-sex marriage is symbolic of liberal approach towards sexual orientation. Evaluation: From a different angle of view, the modern world needs to accept that individuals are different in interest, taste, and opinion. Within this scenario, one cannot prove that traditional marriages successfully lead the partners towards individual freedom and happiness. If one is interested in same-sex marriage, one must be allowed to take independent decisions related t o one’s sexual interest. Evan Gerstmann states that, â€Å"In fact, one of the theories that advocates of same-sex marriage advance most ardently is that the heterosexual marriage monopoly is a form of gender discrimination and, therefore, is subject to intermediate scrutiny†

Molecular Biology Essay Example | Topics and Well Written Essays - 2000 words

Molecular Biology - Essay Example For monoclonal antibody, mice are immunised with purified protein. Mouse splenocytes are collected after the immunisation process and fused with myeloma cells. To obtain monoclonal antibodies individual B cells are fused to myeloma cells and isolated by serial dilution resulting to a fusion product or hybridoma cell line of which can produce one specific antibody for extended periods of time by tissue culture. These hybridomas can be screened and best clones cultured in standard tissue culture facilities. The hybridoma cell line obtained for a given antibody was injected into the peritoneal cavity of mice where it grew and simultaneously produces the antibodies. Ascetic fluid containing the antibodies was harvested from the peritoneal cavity after a period of time. One fusion may produce 1000hybridomas therefore one must choose the most appropriate. This might be the highest infinity mAb but could be the most stable, the least cross reacting, the highest specificity depending on what is required. The advantage of using monoclonal antibodies is that they are monospecific, they tend to reduce cross reactivity and useful in diagnostics such as tissue typing. They are highly reproducible, can use relatively impure antigens to immunise animas, theoretically have limitless supply and can manufacture using recombinant DNA technology plus phage display libraries to produce fully human antibodies of any specificity. Labelling antibodies is useful as it enables detection of antibodies. Currently, the most commonly used are fluorescent labels, enzyme labels, chemiluminescent labels and radioactive labels. These are sometimes amplified using Avidin-Biotin Conjugate system. Some common fluorescent labels include, Fluorescein isothiocyanate, DAPI, Phycoerithrin and Texas red. When using enzyme labels, an enzyme is covalently attached to the

The ban on smoking in public places Essay Example | Topics and Well Written Essays - 1750 words

The ban on smoking in public places - Essay Example Even then researchers had concerns about the hazards of smoking as they pertained to second hand smoke and people who inhaled it(Comfort pp 14). Commonly referred to as passive smoke, those who were around smoke without actually smoking themselves soon proved to have several definitive health risks associated with being near the smoke and inhaling it through passive (second hand methods). â€Å"Medical concerns about the dangers of passive smoking--inhaling other peoples tobacco smoke--can be traced back to the 1920s, and there is also now a widespread consensus that such passive smoking can cause disease. Other peoples tobacco smoke, either from the burning tip of a cigarette or the smoke that is exhaled by the smoker, is classed as a known human carcinogen by the US Environmental Protection Agency(Comfort pp 14). â€Å" For the most part public place for the purpose of legislative ban incorporated any â€Å"enclosed or semi-enclosed area that members of the public have access to which provides a business or a service including workplaces, buildings and public transport(Comfort pp 14). â€Å" â€Å"Direct benefits revolve mainly about respiratory health, and regular exposure to smoke may trigger asthma in infants and young children. The indirect benefits to young peoples health associated with smoke-free policies is seen to relate to the general reinforcement of the messages that non-smoking is now increasingly the norm within the community and would thus help to promote non-smoking lifestyles in future adult generations(Comfort pp 14).†

Group Plan Essay Example | Topics and Well Written Essays - 3750 words

Group Plan - Essay Example 365). A more recent research conducted by Reynolds, Chen and Herbers (2009) indicates that mobility can not only impact students’ academic performance but can also increase the risk of dropping out. This study examined the consequences of student mobility for academic performance and dropout rates in 16 research studies conducted from 1990-2008. Result findings indicate that student mobility accounted for a 1/3 higher rate of both academic under achievement and drop-out rates (1). Rumberger (2002) advices that since nothing can be done about mobility the best response is to inform students and their families of the difficulties that are associated with â€Å"changing schools and how to mitigate them† (p.1). Specifically, Rumberger (2002) recommends that schools should be prepared in advance for the reception of highly mobile students in order to facilitate the transitioning process the moment they arrive. Moreover, schools should set up â€Å"ongoing activities and pro cedures to address the needs of the new student† (Rumberger 2002, p. 2). This group plan is therefore guided by Rumberger’s advice and the documented evidence of the propensity for academic underperformance of students in regular or frequent transition. ... It is difficult to predict the number of students that will be participating in each session, but it is expected to have at least five students and could be as much as twenty. At any rate, teacher representatives from each grade will be asked to participate in the group plan as a means of ensuring that incoming students and their parents/guardians can address any concerns about the curriculum and anything specific to their grade. These teachers are also expected to provide reassurance that they are there for the students and their parents/guardians and when and where they can be contacted. Academic dean, Arthur Baldridge will also be asked to participate in the sessions as frequently as possible. His role is merely to introduce himself and to make himself available to students and their parents/guardians. How Members will be selected Members will be selected by reference to the enrolment register. The enrolment register will inform of new and incoming students. Staff will be selected from among teachers and counsellors based on expertize and availability. The Academic Dean is very important because he administers and plans according to goals set for the student and the academic needs of the students. By participating in the group plan, the Academic Dean will focus special attention on the academic needs of transitioning students. Logistics: The sessions will be conducted once a week for one hour per session for six weeks. The sessions will be held in discussion form and since questionnaires will be distributed in the first and last sessions, it is best to hold the sessions in a classroom. Leadership Skills: As a leader of this

Food Inc Essay Example for Free

Food Inc Essay How is the text you have studied in class constructed to portray certain ideas? Documentaries are usually constructed to portray one point of view, whether it is a negative or positive point of view. Food Inc directed by Robert Kenner, presents a many ideas about how the fast food industry is affecting the ways in which Americans eat. They do this by showing one perspective instead of both. Food Inc doesn’t explore in to detail the positive aspects of fast food; they are just focusing on the negative. They construct the documentary using techniques such as expert opinions, Interviews and statistics to present certain ideas throughout the documentary. The main idea explored throughout the documentary was the animal cruelty caused by humans due to modifying the development of animals. They ways in which they present this ideas is mainly through footage of the animals suffering and the juxtaposition of the animals before they were modified and how the animals are now. The footage of the crowded cows helpless and unable to move creates a setting which portrays a negative feel and creatively making us feel sympathetic towards the animals. The shots of the chickens not being able to walk due to the genetic modifications of the animal, creates the idea of humans purposely provoking animal cruelty. They are changing the ways in which an animal develops for their own needs and generally to make more money. This is clearly shown through the juxtaposition of the â€Å"old† chicken and the â€Å"new† chicken. This Juxtaposition makes us question how it is possible to grow a chicken in half the time yet be double the size? It therefore makes the documentary more engaging as we are starting to question the farmers ourselves and therefore are dragged into believing what the documentary is trying to portray. Another idea explored in the documentary Food Inc is the constant conflict of the prices of healthy foods compared to the prices in fast food restaurants. The ways in which Robert Kenner has constructed the documentary to perceive the fast food outlets being cheaper is through an interview with the Gonzalez family. They are an average sized American family who eat fast food due to their financial status. Kenner used the juxtaposition of the price of a meal at McDonalds to buying a meal at the supermarkets. At McDonalds the Gonzalez family can buy a burger and drink each for 11$, they then show you the Gonzalez family inside a grocery store struggling to buy a lettuce for under 2$ which worked out to be the cost of their whole meal at McDonalds. This makes believe what Kenner is trying to portray and are drawn into believing that fast food is always cheaper than the groceries. However we are not given any cheap healthy displays in the supermarket, instead given with cheap unhealthy items such as 99 cent cokes. Kenner has purposely portrayed the unhealthy items in a negative way to create an opinion that we are being â€Å"forced† in to fast food rather than having the choice of fast food.