434Mod3Case Essay Example | Topics and Well Written Essays - 750 words

434Mod3Case - Essay Example According to the U.S Supreme Court, the video games provide various conflicting situations and conditions to a number of children globally (Totilo, 2010). This also affects their parentage ability as parents are also influenced in this video gaming system. There are many cases involving video games especially in U.S Supreme Court where the offenders claim that video games affects their children upbringing and also leads to violence among them (Totilo, 2010). For example, in mid June the year 2011, the U.S Supreme Court wanted to ban the sale of various video games. However, the first amendment procedures stop them from doing so and later the California Supreme Court decided to ban some violent video games that were considered destructive to children. There are various video game designers in the country including the Nintendo toy games company that was founded in 1889 (Anderson, & Sakamoto, 2008). The firm developed their first video game in 1979 including the first portable video game for children that was designed later in 1980 (Totilo, 2010). The designers of these video games should and must be forced to take the responsibility of various depictions of violent and interpersonal conflicts especially on children of various age groups. The court should properly analyze the effects of video games on children and come out with the best strategy to control this violent act among the children (Anderson, & Sakamoto, 2008). Video games have been available in the global entertainment industry for around thirty years (Totilo, 2011). The recent video games mostly involve the players emotional as well as physically feelings and this makes them have profound impact on children (Totilo, 2010). Currently, around eighty percent of children in the U.S play video games daily and this promote the sales of video games globally (Totilo, 2011). One of major positive impact that video games have on

U can choose from below Essay Example | Topics and Well Written Essays - 1250 words

U can choose from below - Essay Example He realized that the company was one of his working buildings and made a decision of taking all the tests required by the company in order to participate (Steven). Nicholas was immersed in the CRS’s game, though unwillingly. Through his participation in the game, things went out of control making the viewers unsure of the reality. The aim is to explore the plot, techniques, and characters in the film. Plot Nicholas is a wealthy banker with investments. Although his success has been brought about by his personal life, he remains hunted after his father committed suicide. On his forty-eight birthday, he receives a present from his brother, which is a gift card from the CRS Company, which Conrad promised Nicholas that it would change his life. Nicholas doubted but later calls the company. By meeting the fellow members, the game changes Nicholas mind; he applies though irritated by the time it consumed. He is later informed that his application was rejected. By this time, the game has already started and Nicholas highly believes that his life is at risk. He meets Christine who is a waiter and tends to be caught up in the game. Nicholas makes an effort of contacting the police about the company but they find the offices abandoned. At last, Conrad apologizes to Nicholas claiming that through the same company, he was attacked. Since Nicholas had nowhere else to run to, he finds Christine’s’ home and realizes that she is an employee from the SRC Company. She tells Nicholas that they are being watched, and he furiously attacks the cameras thereby forcing them to flee. Christine tells Nicholas that most of his close associates participate in the game. Nicholas later becomes unconscious and is drugged by Christine (Steven). When he wakes up, he finds himself in a cemetery at Mexico where he is forced to sell his golden watch. When he goes back home, he finds his mansion has already been seized. He takes out a gun apologizing to his wife for the neglec t. Nicholas discovers an employee from the SRC who is a famous actor forcing him to make his entries to the SRC. Nicholas almost committed suicide, although unsuccessful. He smashes through a glass roof landing on a giant air bag, which saved his life. He later finds himself with his friends and relatives as well as his colleagues in the game. Conrad is alive and explains that his intensions were for the game to change his brother’s life. Nicholas sees Christine leaving the party, follows her, and shares a cup of coffee, as he waits for the next assignment for the game. How the Actors Portray Key Character Role Reviewing Michael Douglas role as Nicholas Van Orton, examination is on his key traits being a cynic, cold-hearted, high-powered, driven, obsessive, and proud. His obsessive nature is brought out by the way he treats the employees at the investment bank, where he lashes out with demands that are rigid. In terms of being a cynic, he portrays this in a number of ways but in particular, he remains skeptical that the game might make his life fun. He even ends up delaying the call offered by the CRS Company, he also tries to shut others out of his life by showing that he is over the suicide of his father. His high-powered trait and drive are visible in the way he chooses to live his life, with a highly paying investment job and a mansion as his house. However, he is cold-hearted in terms of the inhumane way he treats his secretary (Elizabeth), his ex-wife, and his

Natural habitat Essay Example for Free

Natural habitat Essay Gibson and recorded that, of the 36 participants, 27 infants moved off the centre board. Of this 27 only 3 crossed onto the deep side. These results strongly suggest that almost all babies, at the age of mobility have depth perception abilities. They noticed that most of the infants crawling away from the deep side or cried when called to their mothers. Some infants even touched or patted the glass surface, so they knew that it was solid, but still refused to cross onto it. This is evidence for the idea that humans are particularly visual creatures; even if our other senses are telling us otherwise, we are likely to rely strongly on our vision. Gibson and Walk also noted that several babies moved onto the glass accidentally when trying to move away from it, which shows that accidents like falling off a cliff face will still occur even if the baby has depth perception as they are not as aware of their bodies as adults. Due to the fact that the children were required to be mobile, and this meant the minimum age was six months, Gibson Walk had to use animals as control groups to certify that the babies had not simply learnt depth perception in their first five months through experience and observation in their environment. Animals such as turtles, rats, cats, lambs, kittens, chicks and kids were used. The results of the chicks, kids and lambs were particularly important as all of these animals are precocial and would have had little opportunity in the few hours between birth and being tested to develop depth perception. The chicks, which were all tested within 24 hours of birth all moved onto the shallow side and none crossed over to the deep side. Both kids and lambs also did not step onto the deep side once, and when placed onto the deep side, became distressed and froze still. Rats however, who use their whiskers to navigate, saw little or no preference for either side. This is because they are nocturnal and completely rely on their vibrissae to comprehend their environment. They also found that when the centre board was placed high enough that they could not reach it with their vibrissae, the rats avoided the deep side, showing much more preference for the shallow side. Kittens at four weeks, displayed the same reactions as the lambs, chicks and kids and Gibson and Walk also used dark-reared kittens to investigate the development of the visual system. Kittens that were reared in the dark for the first 27 days of life showed no discrimination between either side. However, when kept in normal lighting conditions, they gained normal depth perception after only one week. Turtles were also tested. Although it was hypothesised that turtles may be attracted to the shiny surface of the glass over the deep side, believing it to resemble water, the turtles also showed levels of depth perception. However, only 76% of turtles managed to avoid the deep side. This large minority suggests that turtles have poor depth perception as a species. This is probably due to their natural habitat; they are less at risk from a fall due to the fact that they spend a majority of their time under water. It is also possible that their depth perception is slightly different to land animals, as they are used to perceiving depths under water, in which distances will appear slightly different. Kids were also used in an alternative test in which they were placed on the shallow side of the glass. The goats appeared fine to stand and move across the surface however when the pattern was lowered, the goats became distressed and froze as soon as it was more than a foot below. The kids never learnt that the glass was solid and therefore safe to stand on, no matter how long they stood on the deep side. Six main conclusions can be draw from this study; human babies have depth perception by the time they are mobile but it is possible this is through experience in their environment before this point. This study also supports the nativist view that we are born with the ability to perceive depth and that the visual system just has to develop for this to be fully functioning (although it does not prove that depth perception is innate). Findings usually fit with the life history and ecological place of the animal being studied (for example, dark reared cats visual systems had not yet developed properly). All animals tested showed depth perception by the age of mobility. Habitat can affect our ability to perceive depth, for example, turtles, whose natural habitat does not require particularly accurate depth perception, show much lower levels of depth perception than other land animals. Studies with rats in which the experimenter changed the size and shape of the pattern to eliminate certain cues suggested that shape and motion cues need to develop over time whereas motion parallax is innate (supported by Yonas et als study into babies depth perception in photographs).

The Impact Of Debt On College Students Economics Essay

The Impact Of Debt On College Students Economics Essay Credit cards and debt, in general, is something that affects everyone on an almost daily basis. It is used in almost any context and has a variety of very important uses that affects life for everyone. One uses credit to buy big-ticket items such as cars or houses but the primary reason one uses credit would be that of convenience. Convenience and the ability to have a short-term load for better cash-flow are normally the reasons why people obtain credit cards. These benefits, when used correctly, can be extremely helpful for most users. However, the key focus in that statement is correct use. The problem with credit occurs when in the hands of the uneducated or inexperienced user. Most frequently, these users are college students. College students run into issues with credit typically in two areas. The primary issue they face is with credit cards, but the other, sometimes unexpected issue is with college tuition and student loans. Because of the many negatives of these issues, Credi t cards and debt, in general, are a significant problem that is currently affecting college students. Credit Cards are a negative influence on students and are a problem for a variety of reasons. One of the most basic problems, and one of the problems that leads into the others, is the issue of the often high unsecured credit lines. Credit card companies, while they usually start out limits at a low level, often increase the limits of teen credit cards rather quickly. According to Silver-Greenberg (2007), Credit card companies have modified their practices for college students, because theyre vulnerable and their parents will usually bail them out (p. 2). The reality is that these credit lines have absolutely nothing to do with a college students ability to pay back the loan and are in no way relational to income. By granting credit lines to college students that are so inflated, it seems like the credit card companies are almost asking for the lines to be abused by the students. The fact is, is that this can be seen very simply just by studying the student population at large. Resea rch by Joo, Grable, and Bagwell (2005) showed that the average balance carried by a college student was around 890 dollars (p. na). A figure this high as an average for college students is way too high. Considering that there are a sizeable amount of college students that are unemployed, it seems rather ridiculous that students would be allowed to charge this amount with no conceivable way of paying back on a routine basis. What makes this whole problem of high balances even worse is the fact that the credit card companies insist upon outrageously high interest rate for college-aged new users. They do this because companies know that college students are more of a risk than regular users. They also do this because they figure that most students will carry a balance and thus, with a higher rate, they have the opportunity to make more money off college students. In addition to just having higher rates for students in general, credit card companies also engage in a practice referred to as universal default. According to Silver-Greenberg (2007), Under universal default, a student who has two credit cards and faithfully makes timely payments on one, but misses a payment on the other, can find that the interest rate hes being charged has been raised to 30% on both cards.(p. 2) Basically, the idea is that if a user is late on one card or account, the user has been late on all of his cards that engage in this practice. This practice exacerbates all of the problems that already exist with credit cards by making it even harder to be good with ones finances. It makes it especially hard for college students, who are new to credit cards in general, because it establishes a very low tolerance for mistakes. In addition, those who least can afford these practices are the ones who have to worry about it. While this practice might be acceptable for adults with an established income and credit history, it hardly makes sense for those just starting out. These high interest rates can be a big problem because two-thirds of all college students have at least one credit card and 15 percent of students have 2 cards or more. (Lee, 2002, p. 10) No doubt those numbers are on the rise as well. Student loans affect the world of credit cards as well. The average graduate from the class of 2007 owes $20,000 in college loans andà ¢Ã¢â€š ¬Ã‚ ¦for 50% of those surveyed their student loan and credit card debt was higher than their current annual salaries (National Poll, 2007, p. n/a) What this proves is that credit is a major burden for those in and out of college. It does not help that credit cards are being used to pay tuition either. Norvilitis (2002) estimates that 20 percent of students have charged tuition and expects that number to rise (p. na). If one does not qualify for a student loan and does not have cash, then a credit card might be the only way they can pay for college. With that in mind, it makes it easier to understand some credit card debt. However, in ad dition to the problems with the usage of credit cards, there are also some problems with the marketing of credit cards in my opinion. Specifically, I believe that the marketing of credit cards on college campuses goes over the line. I believe that getting a credit card should be a personal decision, not just a decision made because you see a booth signing people up at a student center. Giving away free shirts or mugs or food to get someone to sign up for a credit card is just wrong. Finally, Norvilitis (2002) suggested that students who receive cards from tables in a student union have larger debt to income ratios than students whose cards are from another source. (p. n/a) I believe this furthers the reasoning that credit cards should not be advertised on campus. I also believe that credit cards obtained from an on-campus advertiser are not taken as seriously as credit cards obtained in a normal manner. Credit cards have lot of negatives to them and they can cause a great deal of long-term harm. The reason credit cards during the teenage years have such an ability to cause long-term ham is because of the fact that the majority of students and/or teenagers have a relatively short credit history. Realistically, most college students understand that missing payments will probably not be the greatest for their credit, but they have no idea how seriously it affects them. Lee (2002) reports that over 75% of students have never seen their credit report before and that most students are unlikely to ever see their report during their college years (p. NA). This fact makes the effects of credit cards that much more dramatic. When college students are learning how to use their cards and when they make bad decisions regarding payments and carrying large balances, they really have no idea to what extent they are affecting their credit. Considering the fact that most will never see their report u ntil after college, it comes as no surprise that some college students can and will come out of school and not be able to qualify for a simple car loan. What college students do not realize is that simple mistakes in college with credit can significantly impact their future in more ways than one. Martin (2007) states that many employers check credit reports and turn down applicants who have poor credit ratings (p. na). Odds are that most students applying for jobs do not even consider their credit when wondering if they will get the job or not. Another factor that affects a students credit rating is their student loans. While it is not likely that they will miss payments on those loans, the fact is, the large outstanding balances that most carry on these loans counts against them when applying for credit to purchase a home or car. For many, this is a legitimate concern as, according to a National Poll (2007), that among respondents over age 35, 62% are still paying off student loans (p. NA). What this indicates is that credit, whether credit cards or student loans, has a significant effect on ones future. There are a variety of causes for why the use of credit with college students get out of hand and hard to manage. It is particularly hard to make a generalization as to why the majority of college students cannot manage their credit. However, there are many reasons that, in combination with each other, play a role in this problem. One main issue that causes a lot of problems is a lack of education. The majority of college students open credit card accounts without paying a whole lot of attention to what they are getting themselves into. According to Norvilitis (2002), 71% of students had no idea what interest rate they were paying on their particular credit cards. This proves the fact that college students have learned how to use their credit cards but do not understand how their credit cards really work. Most believe that there really is not a whole lot one needs to know about credit cards and the credit card companies must agree because they do not make it easy for any user to real ly learn. In fact, Norvilitis (2002) says that 59% of teens say that explanatory information from credit cards is not helpful or unreadable (p. NA). As a result, the majority of users do not learn about credit. Some do, however, but it is a small number. Personal finance classes are usually offered in high schools to teach just this sort of thing, but unfortunately there is a lack of interest. To illustrate this point, Norvilitis (2002) states that 62% of students had the opportunity to take a personal finances class, only a third actually take it. This should really come as no surprise as the majority of people assume finances should be common sense. This reasoning is what causes problems for the majority of credit card users. The other factor that comes into play regarding credit is family behavior. Generally, as with other behaviors, teens learn from their parents and look to them for guidance. This situation is no different as teens try to emulate their parents in this regard. A ccording to Palmer (2007), 84 percent of teens opened an account at their parents banks (p. na). Parents need to realize that everything that they do financially, whether or not they believe it will be noticed, affects how their teens will use credit. Joo et  al. (2005) found that students whose parents used credit cards often were a lot more likely to show positive attitudes toward credit card use; whereas, students whose parents had problems with credit card use were more likely to have negative attitudes toward using credit cards (p. na).While some parents use credit cards responsibly, some do not. Those that do not are the ones to worry about. If left uneducated, students of these parents will most likely experience issues due to their haphazard use of credit cards. Credit cards will always be misused. There are so many users it would be irresponsible to think otherwise. Furthermore, it can be counted on because there will always be ignorant people who do not pay attention to rules or consequences. However, work can be done to prevent as much misuse as possible. As it stands now, credit cards, and debt in general, are ruining some college students futures. With the lack of regulation when it comes to credit cards for students, it is no surprise. According to Palmer (2007), a survey of graduate students showed that over 50 percent would have liked to have learned more about managing their finances in college. However, without an incentive from somewhere or someone, it is likely that the availability of education in this matter will continue to be hard to come by. Likewise, credit card companies will have to have an incentive to change their practices as well. Hopefully, that day will soon come.

Trail Of Tears :: American America History

Trail Of Tears On September 15, 1830, at Little Dancing Rabbit Creek, the Chiefs of the Choctaw Nation and representatives of the U.S. met to discuss the impact of a bill recently passed by the Congress of the U.S. This bill, with all the same good intentions of those today who believe they know better than we how to conduct our lives, allowed for the removal of all Indian peoples to the West of the Mississippi River. It had been made clear to the Choctaw, that the Whites in Washington cared little for our situation, that either we willingly moved, or by military force we would be moved. We were not ignorant savages, but industrious farmers, merchants, and businessmen of all types. We were educated people, many were Christians. We had an organized system of government and a codified body of law. Some of these people were not even Indians, many strangers and orphans had been taken in over the years. The Chiefs and Warriors signed the treaty, realizing they had no option. For doing this the government officials guaranteed, in the body of the treaty, safe conveyance to our new homes. (Do not forget for a moment that in this treaty, the Choctaw traded 10.3 million acres of land east of the Mississippi for 10.3 acres in Oklahoma and Arkansas that we already owned under previous treaties) Further, it included provisions and monetary annuities, to assist the people to make a new start. One half of the people were to depart almost immediately, the rest the next year. After the signing of the treaty, many saw their land and property sold before their own eyes. The "conveyances" promised turn out to be a forced march. At the point of a gun, the pace killed many of the old, exposure and bad food killed most. Rotten beef and vegetables are poor provisions, even for the idle. Many walked the entire distance without shoes, barely clothed. What supplies were given had been rejected by the whites. This cannot directly blamed on the government, nearly all of this was done by unscrupulous men, interested only in maximizing their profits. They government's fault lies in not being watchful of those taken into their charge. Many of the old and the children died on the road. At each allowed stop, the dead were buried. Hearing of this many escaped. They knew that as they signed the rolls, to be "removed", that this might as well be their death warrants.

Kitchen by Banana Yoshimoto Essay -- English Literature Kitchen Essays

Kitchen by Banana Yoshimoto The path of life is not easy. It is scattered with struggles and hurdles which we must overcome. A rose plant is a good metaphor of life; the flower is soft with a pleasant fragrance but the thorns are prickly and hurt us. Likewise, life has good things like laughter, happiness, hope but it also has some things that hurt us, obstruct us. In Banana Yoshimoto’s novella Kitchen, Mikage Sakurai faces quandaries in her life which hinder her. However, she fights them back with hope and determination. She is aided by the Tanabe’s who help her to fight her dilemmas and struggles. Each character displays a sense of optimism, a hope for survival and the determination to fight back. In a greater sense, this rendering gives the reader a moral teaching that despair does not necessarily result in annihilation. They try to tell us that we must not give up in our lives, come what may. They appear as teachers giving us a lesson how to lead our lives. This rendering makes us feel close to them and think of them as our own friends. This makes them interesting and moving. Mikage is a loner. Throughout her life, she has felt separated from others and feels solitude. She says that despite all the love that surrounds us, we are separated by others physically and mentally which makes each one of us separate, alone. She has suffered great losses; she has lost all her family members. However, after moving into the Tanabe’s apartment, she becomes hopeful for a better life. Mikage wonders â€Å"Wrapped in blankets†¦.in the future† on page 16, that maybe she hadn’t wished for all the loneliness, maybe she had been hoping to think about the future. Here, Mikage reveals the fact that she had completely ignored... ...he darkest of moments and in our moments of despair, we must try to laugh and cheer ourselves. It is a way to become optimistic. In conclusion, this story is of great value to any reader because it portrays a real life story. The characters appear very real to us because of their simplicity and unusualness. This makes us endearing to these characters, we feel attached to them, sympathy towards them. Each character contributes to a greater understanding of the definition of life and the way to live. Each character is determined that they would not fail, they would not give up; they would continue to fight on despite any barrier, any resistance. They teach us that death is not the end of despair, there are several others way to live on despite being clouded by darkness and uncertainty. This makes the reader respect the characters and feel close to them.

Outline of Carbon and Molecular Diversity of Life

Chapter 4 Carbon and the Molecular Diversity of Life Lecture Outline Overview: Carbon – The Backbone of Biological Molecules * Although cells are 70–95% water, the rest consists mostly of carbon-based compounds. * Carbon is unparalleled in its ability to form large, complex, and diverse molecules. * Carbon accounts for the diversity of biological molecules and has made possible the great diversity of living things. * Proteins, DNA, carbohydrates, and other molecules that distinguish living matter from inorganic material are all composed of carbon atoms bonded to each other and to atoms of other elements. These other elements commonly include hydrogen (H), oxygen (O), nitrogen (N), sulfur (S), and phosphorus (P). (CHONPS) Concept 4. 1 Organic chemistry is the study of carbon compounds * The study of carbon compounds, organic chemistry, deals with any compound with carbon (organic compounds). *Organic compounds can range from simple molecules, such as CO2 or CH4, to compl ex molecules such as proteins, which may weigh more than 100,000 daltons. * The overall percentages of the major elements of life (C, H, O, N, S, and P) are quite uniform from one organism to another. However, because of carbon’s versatility, these few elements can be combined to build an inexhaustible variety of organic molecules. * Variations in organic molecules can distinguish even between individuals of a single species. * The science of organic chemistry began in attempts to purify and improve the yield of products obtained from other organisms. * Initially, chemists learned to synthesize simple compounds in the laboratory, but had no success with more complex compounds.The Swedish chemist Jons Jacob Berzelius was the first to make a distinction between organic compounds that seemed to arise only in living organisms and inorganic compounds that were found in the nonliving world. * This led early organic chemists to propose vitalism, the belief that physical and chemical laws did not apply to living things. * Support for vitalism began to wane as organic chemists learned to synthesize complex organic compounds in the laboratory. * In the early 1800s, the German chemist Friedrich Wohler and his students were able to synthesize urea from totally inorganic materials.In 1953, Stanley Miller at the University of Chicago set up a laboratory simulation of chemical conditions on the primitive Earth and demonstrated the spontaneous synthesis of organic compounds. * Such spontaneous synthesis of organic compounds may have been an early stage in the origin of life. * Organic chemists finally rejected vitalism and embraced mechanism, accepting that the same physical and chemical laws govern all natural phenomena including the processes of life. * Organic chemistry was redefined as the study of carbon compounds regardless of their origin. Organisms do produce the majority of organic compounds. * The laws of chemistry apply to inorganic and organic compounds ali ke. Concept 4. 2 Carbon atoms can form diverse molecules by bonding to four other atoms *With a total of 6 electrons, a carbon atom has 2 in the first electron shell and 4 in the second shell. * Carbon has little tendency to form ionic bonds by losing or gaining 4 electrons to complete its valence shell. * Instead, carbon usually completes its valence shell by sharing electrons with other atoms in four covalent bonds. This tetravalence by carbon makes large, complex molecules possible. * When carbon forms covalent bonds with four other atoms, they are arranged at the corners of an imaginary tetrahedron with bond angles of 109. 5Â °. * In molecules with multiple carbons, every carbon bonded to four other atoms has a tetrahedral shape. * However, when two carbon atoms are joined by a double bond, all bonds around those carbons are in the same plane and have a flat, three-dimensional structure. * The three-dimensional shape of an organic molecule determines its function. The electron configuration of carbon makes it capable of forming covalent bonds with many different elements. * The valences of carbon and its partners can be viewed as the building code that governs the architecture of organic molecules. *In carbon dioxide, one carbon atom forms two double bonds with two different oxygen atoms. * In the structural formula, O=C=O, each line represents a pair of shared electrons. This arrangement completes the valence shells of all atoms in the molecule. * While CO2 can be classified as either organic or inorganic, its importance to the living world is clear. CO2 is the source of carbon for all organic molecules found in organisms. It is usually fixed into organic molecules by the process of photosynthesis. * Urea, CO(NH2)2, is another simple organic molecule in which each atom forms covalent bonds to complete its valence shell. Variation in carbon skeletons contributes to the diversity of organic molecules. * Carbon chains form the skeletons of most organic mole cules. * The skeletons vary in length and may be straight, branched, or arranged in closed rings. *The carbon skeletons may include double bonds. Atoms of other elements can be bonded to the atoms of the carbon skeleton. * Hydrocarbons are organic molecules that consist of only carbon and hydrogen atoms. * Hydrocarbons are the major component of petroleum, a fossil fuel that consists of the partially decomposed remains of organisms that lived millions of years ago. * Fats are biological molecules that have long hydrocarbon tails attached to a nonhydrocarbon component. * Petroleum and fat are hydrophobic compounds that cannot dissolve in water because of their many nonpolar carbon-to-hydrogen bonds. Isomers are compounds that have the same molecular formula but different structures and, therefore, different chemical properties. * For example, butane and isobutane have the same molecular formula, C4H10, but butane has a straight skeleton and isobutane has a branched skeleton. * The tw o butanes are structural isomers, molecules that have the same molecular formula but differ in the covalent arrangement of atoms. * Geometric isomers are compounds with the same covalent partnerships that differ in the spatial arrangement of atoms around a carbon–carbon double bond. The double bond does not allow atoms to rotate freely around the bond axis. *The biochemistry of vision involves a light-induced change in the structure of rhodopsin in the retina from one geometric isomer to another. * Enantiomers are molecules that are mirror images of each other. * Enantiomers are possible when four different atoms or groups of atoms are bonded to a carbon. * In this case, the four groups can be arranged in space in two different ways that are mirror images. * They are like left-handed and right-handed versions of the molecule. * Usually one is biologically active, while the other is inactive. Even subtle structural differences in two enantiomers have important functional signi ficance because of emergent properties from specific arrangements of atoms. * One enantiomer of the drug thalidomide reduced morning sickness, the desired effect, but the other isomer caused severe birth defects. *The L-dopa isomer is an effective treatment of Parkinson’s disease, but the D-dopa isomer is inactive. Concept 4. 3 Functional groups are the parts of molecules involved in chemical reactions * The components of organic molecules that are most commonly involved in chemical reactions are known as functional groups. If we consider hydrocarbons to be the simplest organic molecules, we can view functional groups as attachments that replace one or more of the hydrogen atoms bonded to the carbon skeleton of the hydrocarbon. * Each functional group behaves consistently from one organic molecule to another. * The number and arrangement of functional groups help give each molecule its unique properties. * As an example, the basic structure of testosterone (a male sex hormone ) and estradiol (a female sex hormone) is the same. *Both are steroids with four fused carbon rings, but they differ in the functional groups attached to the rings. These functional groups interact with different targets in the body. * There are six functional groups that are most important to the chemistry of life: hydroxyl, carbonyl, carboxyl, amino, sulfhydryl, and phosphate groups. * All are hydrophilic and increase the solubility of organic compounds in water. * In a hydroxyl group (—OH), a hydrogen atom forms a polar covalent bond with an oxygen atom, which forms a polar covalent bond to the carbon skeleton. * Because of these polar covalent bonds, hydroxyl groups increase the solubility of organic molecules. Organic compounds with hydroxyl groups are alcohols, and their names typically end in -ol. * A carbonyl group (>CO) consists of an oxygen atom joined to the carbon skeleton by a double bond.* If the carbonyl group is on the end of the skeleton, the compound is a n aldehyde. * If the carbonyl group is within the carbon skeleton, then the compound is a ketone. * Isomers with aldehydes versus ketones have different properties. * A carboxyl group (—COOH) consists of a carbon atom with a double bond to an oxygen atom and a single bond to the oxygen of a hydroxyl group. * Compounds with carboxyl groups are carboxylic acids. A carboxyl group acts as an acid because the combined electronegativities of the two adjacent oxygen atoms increase the dissociation of hydrogen as an ion (H+). * An amino group (—NH2) consists of a nitrogen atom bonded to two hydrogen atoms and the carbon skeleton. * Organic compounds with amino groups are amines. * The amino group acts as a base because the amino group can pick up a hydrogen ion (H+) from the solution. * Amino acids, the building blocks of proteins, have amino and carboxyl groups. *A sulfhydryl group (—SH) consists of a sulfur atom bonded to a hydrogen atom and to the backbone. This grou p resembles a hydroxyl group in shape. * Organic molecules with sulfhydryl groups are thiols. * Two sulfhydryl groups can interact to help stabilize the structure of proteins. * A phosphate group (—OPO32? ) consists of a phosphorus atom bound to four oxygen atoms (three with single bonds and one with a double bond). * A phosphate group connects to the carbon backbone via one of its oxygen atoms. * Phosphate groups are anions with two negative charges, as two protons have dissociated from the oxygen atoms. * One function of phosphate groups is to transfer energy between organic molecules.Adenosine triphosphate, or ATP, is the primary energy-transferring molecule in living cells. These are the chemical elements of life. * Living matter consists mainly of carbon, oxygen, hydrogen, and nitrogen, with smaller amounts of sulfur and phosphorus. * These elements are linked by strong covalent bonds. * Carbon, with its four covalent bonds, is the basic building block in molecular archi tecture. * The great diversity of organic molecules with their special properties emerges from the unique arrangement of the carbon skeleton and the functional groups attached to the skeleton.