Diffusion Across Biological Membranes Essay Example for Free

Diffusion Across Biological Membranes Essay From the cell simulation modal made, it has explained about the aspects of diffusion and indicator solution (chemical testing) to test for particular substances. From the observation made, iodine and glucose have greater concentration due to small molecular size and also they are monomers. It means their molecules are smaller. Thus, it diffused out to create a state of equilibrium. On the other hand, starch molecules did not move by diffusion across a membrane into or out of the cell due to the large molecular side. This is because many repeated glucose subunits are found in starch structure. Starch is a polymer. This is the reason why the water in the beaker or 1 inch dialysis tube did not turn dark blue as no starch molecules diffuse out. However, the liquid outside of cell was cloudy. When iodine indicator and Benedict’s test, tested for presence of iodine and glucose respectively, the colour change was not very distinctive. Hence, we came to a rationale that more time could have needed for glucose and iodine achieve diffusion as 1 hour was not enough to complete as perhaps molecules on one side of a membrane become trapped by binding to macromolecule. On the other hand, perhaps water in the beaker could have been too diluted so could not detect the presence of glucose and iodine using indicators. This process is termed as osmosis. In osmosis, molecules also travel from higher concentration to lower concentration. However, osmosis only occurs in water. Water molecules are polar and small enough to pass through the membrane. Therefore, from this experiment, we can understand that water is essential for cells survival. However, too much of water will result in hypotonic. ells is placed with a lower concentration, then osmotic pressure of the extracellular fluid is less than intracellular fluid. As a result, water flow into the cell causing it to swell and undergo lysis (burst). Likewise, if a cell is placed into a solution with higher osmotic concentration than the intracellular fluid such as salt solution. The osmotic pressure of the extracellular fluid will exceed that of the intracellular fluid casing the cell to shrink and crenate. Hence, it’s hypertonic. This explains why when a small dose of fertilizer can enhance plant growth but over fertilization can kill the plant. Fertilization has salt and salt dehydrates the cytoplasm in the cell and would dry up making the cells shrivel up and die. Iodine indicators and Benedict’s solution proved that when a substance reacts with its indicator solution, a reaction will occur and cause a colour change. In this case, iodine test used to test for the presence of iodine in the solution and Benedict’s solution is use to detect glucose. It is important for Benedict’s solution to be heated as it’s a way to prove that it is the mixing of the two that creates the bright orange colour. If the benedict’s solutions were to be heated separately or the solution to be heated there will not be any results produced to test the presence of glucose. The indicator solution will react only if the substance is meant for is present, then it will react. Else there would not be any changes to observe. Indicators come in handy when dealing with unknown samples of ingredients to prove what a substance is. A negative control is used yield a negative result. This is to ensure that all the reagents are pure and there is no contamination that will give a false result. Conclusion In conclusion, we can conclude that diffusion occur spontaneously and molecular size and charges matters when molecule pass thought cell membrane unless its molecular size is small and it’s a monomer diffusion will occur spontaneously. However, if the molecular size is big and it might also hinders the passage way for smaller molecules to diffuse to a higher concentration to lower concentration to bring it to an equilibrium state. We also concluded that cell should maintain a isotonic environment to conduct its activity smoothly else in hypertonic or hypotonic, it will burst or shrivel and eventually kills the cell. Therefore, diffusion and osmosis are types of passive transport and happens spontaneously.

Cosquer Cave :: Place Descriptive Essays

Cosquer Cave In 1985, while scuba diving in Cape Morgiou, near Marseilles, France, Henri Cosquer discovered a narrow 175-meter, air-filled tunnel 37 meters below the sea (â€Å"The Cosquer Cave†). The tunnel, unbeknownst to him, lead to one of the world’s most treasured Paleolithic art-filled caves. During the Paleolithic age, Cosquer cave was much more accessible than it is today. Researchers say that at the times the art was created, the cave was probably only 11 kilometers from the coast and 80 meters above sea level (Jaobs). Since then, the giant glaciers of the period have melted and the Mediterranean Sea has risen, preserving this magnificent display of ancient art. Oblivious to the historical importance of his find, Cosquer kept the cave secret until a return visit in July of 1991 when he sighted what seemed to be a red, stenciled human hand painted on the side of the cave (Clottes 14). Excited by this discovery, Cosquer invited several fellow divers including Yann Gogan, Jean-Claude Cayol, Pascal Oriol, Cendrine Cosquer, and Thierry Pà ©lissier to further examine the cave with him (Clottes 14). The hand, as it turned out, was only the first of approximately 142 ancient paintings and engravings that appear on the walls and ceilings of Cosquer cave (â€Å"Accessing Cosquer Cave†). The cave consists of several narrow tunnels, some of which are less than one meter high, and two main chambers that are covered with calcite crystals (Clottes 48). Throughout the cave are finger grooves, which the artists were able to carve into the weather-softened stone walls (Clottes 59). After recording proof of the discovery, Henri Cosquer informed the French Ministry of Culture. They assigned Jean Clottes and Jean Courtin to study the cave for further research. In the last nine years scientists and archaeologists have performed approximately two dozen radiocarbon datings (Jaobs). This makes Cosquer the most extensively dated cave in the world (â€Å"Accessing Cosquer Cave†). Through these thorough studies, researchers have discovered that the images were created during two separate phases. The first phase dates around –27,000, and includes the handprints and some geometric designs that were found (Duckeck). After that, there is an 8000 year gap in which no one seems to have used the cave (Jaobs). The second phase is between -19,000 and –18,000. It was in this phase that the animal images were created (Duckeck). Of the images depicted in the cave, over two-thirds are engraved and most are of horses (Duckeck).

End User

End user database Description A simple, searchable online database made up of structured records whose content Is generated by the participants. The records normally contain personal Information relating to a set of individuals. The database is self-perpetuating in that in order to access It, participants are usually made to submit their own information. Usually incorporates instant messaging capability for connecting participants based on a match. Purpose The purpose of this method Is to ‘find' others with matching needs or take control ever your data.For example, matching interests in order to connect or trade. Participants benefit from being able to use a single touch point for identifying matches and are able to compare offers from a pool of potentially similar records. Improves the likelihood of success through pre-vetting. Strengths * Can offer anonymity while retaining high levels of personal detail and control over how these are shared (I. E. Citizen held records). * Ma y include advanced testing to determine compatibility or matches between participants and records. Useful research tool, e. G. For determining average prices. Weaknesses * There is often a charge to access the database. * Sometimes there can be a stigma associated with being on a private database (e. G. If participants are looking to date). * Can soon become out of date and usefulness out of perspective it inactive records are not deleted. End users are those persons who interact with the application directly. They are responsible to Insert, delete and update data in the database. They get Information from the system as and when required.Types: a) Direct users: Direct users are the users who SE the computer, database system directly, by following instructions provided in the user interface. They interact using the application programs already developed, for getting the desired result. E. G. People at railway reservation counters, who directly Interact with database. B) Indirect user s: Indirect users are those users, who desire benefit from the work of DB'S Indirectly. They use the outputs generated by the programs, for decision making or any other purpose. They are Just concerned with the output and are not bothered about the programming part.There are several categories of end users: 1 . Casual end users occasionally access the database, but they may need different information each time. They use a sophisticated database query language to specify their requests and are typically middle- or high-level managers or other occasional browsers. 2. Naive or parametric end users make up a sizable portion of database end users. Their main job function revolves around constantly querying and updating the Off database, using standard types to queries and updates-called canned transactions- that have been carefully programmed and tested.The tasks that such users perform are varied: Bank tellers check account balances and post withdrawals and deposits. Reservation clerks fur airlines, hotels, and car rental companies check availability for a given request and make reservations. Clerks at receiving stations for courier mail enter package identifications via bar codes and descriptive information through buttons to update a central database of received and in-transit packages. 3.Sophisticated end users include engineers, scientists, business analysts, and others who thoroughly familiarize themselves with the facilities of the DB'S so as to implement their applications to meet their complex requirements. 4. Stand-alone users maintain personal databases by using ready-made program packages that provide easy-to-use menu-based or graphics-based interfaces. An example is the user of a tax package that stores a variety of personal financial data for tax purposes.

Childhood Obesity And Its Effects On Children - 985 Words

Despite recent declines in the prevalence among preschool-aged children, obesity among children is still too high. For children and adolescents aged 2-19 years, the prevalence of obesity has remained fairly stable at about 17% and affects about 12.7 million children and adolescents for the past decade (CDC). Childhood obesity does not only affect children, but also has many long term health effects on our children as they get older, including, an increased risk of type 2 diabetes in both childhood and adulthood. (2). Researchers estimate that if obesity trends continue, obesity related medical costs, alone, could rise by $43 to $66 billion each year in the United States by 2030. (1) A major factor in childhood obesity is the inadequate amount of physical activity children are getting, as well as the school lunches that are being provided to the kids. The accessibility of competitive foods which includes things like vending machines, student stores and items a la carte in schools has been linked with negative dietary behaviors, including higher saturated fat intake, higher sweetened beverage intake, and less fruit and vegetable intake,(3) thus resulting in obesity among our children and adolescents. Research suggests that by making sure children are getting healthy school meals and getting enough physical activity in their day it will decrease their chances of having childhood obesity (3). The purpose of this review was to determine the role, school lunches and physicalShow MoreRelatedChildhood Obesity And Its Effects On Children1188 Words   |  5 Pagesbehaviors adopted by children affect their mental and physical health. Studies have shown that there is a link between what children see in advertisements and the lifestyle choices they make. Studies also showed that children who viewed advertisements showing healthy eating were more likely to engage in healthy eating habits (Carter and Maria). There are large amounts of advertisements for foods and drinks hig h in fat and sugar. Many studies show that there is a link between childhood obesity and advertisingRead MoreChildhood Obesity And Its Effect On Children1273 Words   |  6 Pagesincline, childhood obesity is one of the most important issue. Often times, parents are willing to do anything for their child with the idea that it is â€Å"healthy.† When they figure out that not everything is healthy, some even take efforts to sue the company. Parents do not realize the underlying factors that cause this type of obesity. Childhood obesity can be a result of many factors in this upcoming society. Many consider genetics and hormonal development as a proof for childhood obesity. HoweverRead MoreChildhood Obesity And Its Effects On Children1093 Words   |  5 Pages Obesity is a serious, sometimes fatal condition in which a person is significantly overweight for his or her age and height. Many children suffer from this condition all over the world. Childhood obesity is one of the mo st increasing health threats that the United States faces. Many researchers ask how children get to be so overly obese and unhealthy. They have come up with ways to somehow prevent it; however, the rates of the growing disease have grown rapidly over the years. It causes many problemsRead MoreChildhood Obesity And Its Effects On Children1727 Words   |  7 PagesEnding Childhood Obesity Juanita was born at an average weight of six pounds, but now at 10-months-old she weights a whopping 44 pounds. Juanita has gained over seven times her original weight and is at the weight of an average five year old. Doctors say by age two or three Juanita could develop type two diabetes (She Was Just Ten Months). Unfortunately, this is not a rare for many children all over the world; many children suffer from the exact same situation Juanita has been put into. ChildhoodRead MoreChildhood Obesity And Its Effects On Children Essay1645 Words   |  7 PagesChildhood obesity introduce In addition to the physical harm, obesity and negative psychological impact on children. This is a high risk factors of childhood obesity, which can lead to high blood pressure, high cholesterol, diabetes and cardiovascular disease. Obese children always lower than that of healthy children intelligence and operators. Their activities, learning and communication ability is very low, and their depression and low self-esteem can make the children s sensitivity to interpersonalRead MoreChildhood Obesity And Its Effects On Children920 Words   |  4 PagesAccess to fresh fruits, vegetables and nutritious meals is an important component in combating childhood obesity. Socioeconomic conditions can limit access to quality food for many children. Without the ability to consume nutritious, low calorie food portions children are at risk for developing health conditions. In 2011, 20.6% of households with children in the U.S. have experienced food insecurity and it has been associated with negative health and development outcomes including more frequentRead MoreChildhood Obesity And Its Effects On Children945 Words   |  4 PagesDid you know that childhood obesity has tripled in last 30 years? According to Spark, a web site about childhood obesity, a child is considered obese if their BMI(Body Mass Index) is 30 or higher. This is a serious medical condition. It can lead to a variety of serious diseases and have physiological and psycological impact on the children, moreover it can cause issues in their social lives. Childhood obesity is prevalent in both developed and developing countries. Home, schools, and the communityRead MoreChildhood Obesity And Its Effect On Children1614 Words   |  7 PagesChildhood Obesity has become one of the leading causes of death in our nation today. Sadly, our society in whole is one of the heaviest. Putting an emp hasis on the fact that â€Å"obesity rates among children of all ages are dramatically higher then they were a generation ago† (Green). Society has made it, with little to no trouble, that kids can get what they want, when they want it. Children are unaware of the harm and trauma they are putting their bodies through at such a young age. Childhood obesityRead MoreChildhood Obesity And Its Effects On Children1422 Words   |  6 PagesThe United States, the busiest country on over the world, is being threatened by the obesity, especially children. Compare with the past 30 years, in 2012, the number of children are obese increases doubled (Childhood Obesity Facts). The major elements that lead to the childhood obesity not only come from the invisible factor are family’s gene, but also the environment grow them up as school and the influence of technology in the modern society. But if the parent and school have a positive behaviorRead MoreChildhood Obesity And Its Effects On Children1871 Words   |  8 PagesChildhood obesity has been more than doubled in the past 30 years and it increased from 7% in 1980 to nearly 18% in 2012 according to the USA Centers for Disease Control and Prevention. Childhood obesity is a very genuine therapeutic condition that influences children. It happens when the child is above the typical weight for his or her age and height. Childhood obesity is a serious medical condition that affects both the children and adults. Childhood obesity is not only an issue in developed countries