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Cell transport mechanisms essay 2015
Cell transport mechanisms essay 2015
Experiment of osmosis in living organism
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Homeostasis is essential to the cell’s survival. The cell membrane is responsible for homeostasis. The membrane has a selective permeability which means what moves in and out of the cell is regulated. Amino acids, sugars, oxygen, sodium, and potassium are examples of substances that enter the cell. Waste products and carbon dioxide are removed from the cell. All of these substances cross the membrane in a variety of ways. From diffusion and osmosis, to active transport the traffic through the cell membrane is regulated.
Diffusion is the movement of molecules form one area of higher concentration to an area of lower concentration. Concentration gradient causes the molecules to move from higher concentration to a lower concentration. The side of the membrane that has the higher concentration is said to have the concentration gradient. It drives diffusion because substances always move down their concentration gradient. The pressure gradient also plays a role in diffusion. Where this is a pressure gradient there is motion of molecules. The pressure gradient is a difference in pressure between two different points. If the concentration of one side of the membrane is greater than the molecules will travel from the higher to lower concentration.
Eventually there will be a dynamic equilibrium and there will be no net movement of molecules from one side to the other.
Osmosis is the diffusion of water. Like diffusion, the water moves from a region of higher water potential to a region of lower water potential. Solutions have three different stages that the solutes can be classified in: isotonic, hypertonic, and hypotonic. Isotonic is when the solutions have equal amounts of solutes. Like equilibrium, there is no net change in the amount of water in either solution. When the solutions have different concentration of solutes then the one with less solute is hypotonic and the one with more solute is hypertonic.
Hypotonic takes in the solute from the hypertonic side that gives away the solute. There will be a net movement in these types of solution.
The molecules will move from the hypotonic solution into the hypertonic solution. The third way a substance can cross the cell membrane is through facilitated diffusion. This occurs when special carrier proteins carry solutes dissolved in the water across the membrane by using active transport. When the concentration gradient can not allow travel from one side of the membrane to the other fast enough for the cell’s nutritional needs, then facilitated diffusion is used. The transport protein is specialized for the solute it is carrying, just as enzymes are specialized for their substrate. The transport protein can be
In life, it is critical to understand what substances can permeate the cell membrane. This is important because the substances that are able to permeate the cell membrane can be necessary for the cell to function. Likewise, it is important to have a semi-permeable membrane in the cell due to the fact that it can help guard against harmful items that want to enter the cell. In addition, it is critical to understand how water moves through the cell through osmosis because if solute concentration is unregulated, net osmosis can occur outside or inside the cell, causing issues such as plasmolysis and cytolysis. The plasma membrane of a cell can be modeled various ways, but dialysis tubing is especially helpful to model what substances will diffuse or be transported out of a cell membrane. The experiment seeks to expose what substances would be permeable to the cell membrane through the use of dialysis tubing, starch, glucose, salt, and various solute indicators. However, before analyzing which of the solutes (starch, glucose, and salt) is likely to pass through the membrane, it is critical to understand how the dialysis tubing compares to the cell membrane.
Language can bring people together but can also isolate. The United States is known as a melting pot, not only does that refer to culture but also the many different languages. We know of language barriers, but very seldom do we think of the language barriers within our borders. Even with the language barriers it solidifies the need for a national language, the United States of America should allow the freedom to express one’s culture while maintaining English as our national language, therefore offering common ground to its citizens.
Today’s commercials cloud the viewers’ brains with meaningless ritzy camera angles and beautiful models to divert viewers from the true meaning of the commercials. The advertisers just want consumers to spend all of their hard-earned money on their brand of products. The “Pepsi” and “Heineken” commercials are perfect examples of what Dave Barry is trying to point out in his essay, “Red, White and Beer.” He emphasizes that commercial advertisements need to make viewers think that by choosing their brands of products, viewers are helping out American society. As Rita Dove’s essay “Loose Ends” argues, people prefer this fantasy of television to the reality of their own lives. Because viewers prefer fantasy to reality, they become fixated on the fantasy, and according to Marie Winn in “Television Addiction,” this can ultimately lead to a serious addiction to television. But, one must admit that the clever tactics of the commercial advertisers are beyond compare. Who would have thought the half naked-blondes holding soda cans and American men refusing commitment would have caught viewers’ attention?
Advertising is so prominent in American culture, and even the world at large, that this media form becomes reflective of the values and expectations of the nation’s society at large.
The Importance of Diffusion to Living Organisms Diffusion is basically the movement of chemical species (ions or molecules) under the influence of concentration difference. The species will move from the high concentration area to the low concentration area till the concentration is consistent in the whole system. Diffusion mostly occurs in gases and liquids as these can move freely. The main features of an efficient diffusion system would be that it has a large surface area, thin membrane and a continuous supply of substances. A large surface area is needed so that high amount of substances can be exchanged at a time while the thin membrane means that the diffusion pathway would be short so that it is more efficient.
What is the official language or the United States? 90% of the people would answer English, but guess again. The United States doesn’t have an official language. The subject of English as the official language of the United States has been covered intensively by the world press over the past decade. Declaring it the official language of United States can make an improvement in many areas, and is very relevant for future generations. Even though English-only movement has close connections to restrictionist and anti-immigration organizations. Which suggests that the movement has a wider, more far-reaching, and more negative agenda than simply advocating an official English language policy. English should be the official language of United States because making it the official language of the United States refers solely to the language of the government, not of the people, private business, classrooms, etc., and in 1990 US census reported that 97.1% of the US population speak English.
If a plant cell is places in a hypotonic solution the cell has a lower water concentration to that of the solution. Water will move into the cell by osmosis from a high water concentration outside the cell to a lower water concentration inside the cell through a selectively permeable membrane. The cell becomes turbid
The United States is made up of many different ethic groups. These groups vary from Latinos, Asian American, African American, Pacific Islanders, Native Americans, and etc. These ethnic groups come into America speaking many different languages. However, many people are still surprised to learn that the United States has no official language. Many assume that English is the official language of the United States. But despite efforts over the years, the United States has no official language. Because the United States has no official language, it is suffering with large costs. These large costs will lead us on a road to wasteful government expenses, language battles that fuel ethnic resentment, and in the long run serious ethnic and linguistic separatist movements. An official English legislation is the answer to the problem.
Many companies spend over millions of dollars advertising every year, and these advertisements influence how an individual thinks and acts in a society. It becomes a significant aspect of our lives whether it has come to our acknowledgment or not. It influences us to the extent we believe the information presented in the media are “normal”. To be precise, advertisements create and define the social norms. These concepts are strongly built into my mind since a young age, especially the gender roles between men and women.
English as the official language of the United States could benefit the U.S. Government and America as a whole. America has long since been a multicultural nation and has been an English speaking nation since it was founded. The constitutional and federal documents are all in English, which furthers the American people, believing English should be our official language. The majority of states already have English as their official language, for English has always provided a much needed cohesion to our diverse citizens since it was founded.
Over the span of half a century, the medical profession has witnessed a catastrophic shift in the patient-physician relationship. As the manufacturing of new pharmaceuticals and the number of patients under a physician’s care continue to rise, doctor’s are finding it difficult to employ the time-honored principles listed within the Hippocratic Oath. This oath, written in 430 BC by the Greek Physician, Hippocrates, was the first document to state the responsibilities of a physician to his patient (vadscorner, pg 2). Hippocrates believed that it was the physician’s duty, as a healer, to treat the patient infected with the disease to the best of his ability, and not to treat the disease (Hippocrates, pg 1 ). He believed that the patient was, above all, the most important aspect involved in the healing process. With the rise in the number of patients under a physician’s care and the stringent rules by which each doctor must abide, many doctor’s are finding that they are unable to devote ample time to become acquainted with their patients (spiralnotebook, pg 1). Furthermore, as newly acquired information regarding illnesses becomes available on the internet, patients are seeking the advice of multiple physicians (Changing, pg 3). These differences between patients and their physicians, as well as numerous others, have caused rifts in the patient-doctor relationship.
It's just outright disrespectful to growing minorities to make English an official language and could harm the economy. In order to increase the equality and progress the nation, it more fitting to make the United States have no official language and not discriminate or deter from completing their dreams in America. As times change and minorities grow and majorities decrease, the
Osmosis is the passage of water molecules from a weaker solution to a stronger solution through a partially permeable membrane. A partially permeable membrane only allows small molecules to pass through, so the larger molecules remain in the solution they originated in. Solute molecule [IMAGE] [IMAGE] Water molecule [IMAGE] The water molecules move into the more concentrated solution. When water enters a plant cell it swells up. The water pushes against the cell wall and the cell eventually contains all that it can hold.
Since language is an essential part of culture, and America has no national language, then America is not tied together with one culture. There are reasons why the U.S. Government has not declared an official language. The most important being that an official language of English would promote xenophobia, making the English speaking afraid of new immigrants or vice versa. It would also deprive the American citizens who do not speak English of some of their basic rights. For example, how could someone vote, or take a driving test, if they do not know the language. On the other hand, immigrants would benefit if they were forced to learn a national language in America. They would be able to receive a better education, find a better job, and participate more completely in society (Gallegos, 1994).
I personally believe that in our nation there needs to be a main language, not 3 or 4 or 1200. George Washington wasn’t giving orders at Valley Forge in Russian he was speaking English. Abe Lincoln didn’t give the Gettysburgh Address in Portuguese. It’s not to much to ask for every American citizen to be able to speak English fluently. No one is forced to live here, and if you refuse to adapt you probably shouldn’t be living here. If you want to speak German by all means go ahead and do so, but do it back in Germany. While you’re in America however, we speak English, and if you don’t know it you’re in trouble. The conflict is over rated. It’s not a matter of racism or of any other kind of hatred. It’s a simple matter of principle. American’s speak English it’s not to much to ask.