Peter Mitchell (1920 - 1992) Chemiosmotic Hypothesis Essays

Peter Mitchell (1920 - 1992) : Chemiosmotic Hypothesis Peter Mitchell's 1961 paper introducing the chemiosmotic hypothesis started a revolution which has echoed beyond bioenergetics to all biology, and shaped our understanding of the fundamental mechanisms of biological energy conservation, ion and metabolite transport, bacterial motility, organelle structure and biosynthesis, membrane structure and function, homeostasis, the evolution of the eukaryote cell, and indeed every aspect of life in which these processes play a role. The Nobel Prize for Chemistry in 1978, awarded to Peter Mitchell as the sole recipient, recognized his predominant contribution towards establishing the validity of the chemiosmotic hypothesis, and ipso facto, the long struggle to convince an initially hostile establishment. The seeds of the chemiosmotic hypothesis, which lay in Peter's attempts to understand bacterial transport and homeostasis, were pollinated by the earlier ideas of H. Lundergard, Robert Robertson, and Robert Davies and A.G. Ogston, on the coupling of electron transport and ATP synthesis to proton gradients. Mitchell's 1961 paper outlined the hypothesis in the form of several postulates which could be subjected to test. In retrospect, it was a great strength of this first paper that Peter did not go into too much detail; the ideas were new and strange, and were introduced to a field dominated by a few major laboratories with their own different ideas about how the coupling between electron transport and phosphorylation occurred. It is interesting to look back and remember how sparse the clues were on which the hypothesis was based. At the time, the chemical hypothesis, based on analogy with Ephraim Racker's mechanism of substrate level phosphorylation linked to triose phosphate oxidati on, seemed secure. A few niggling difficulties were apparent. Why did so many different reagents act as uncouplers? Why were the enzymes of oxidative phosphorylation associated with the mitochondrial membrane? Why did coupling seem so dependent on the maintenance of structure? How did mitochondria maintain their osmotic balance? How did substrates get in and out? But these must have seemed second-order problems to the main protagonists. It was these niggles that Mitchell's hypothesis addressed. I first met Peter in 1962 when he visited Brian Chappell in Cambridge to talk mitochondriology. I was in my second year of Ph.D. research, and becoming familiar with the field. Brian had, at the start of my apprenticeship, set me to work in the library, with Peter's 1961 paper as a starting point. I must confess that I had little idea at the time of the importance of the paper; I didn't know enough, either of the background bioenergetics or the physical chemistry, to understand what the issues were. But by the time of Peter's visit, I had become involved in the work on mitochondrial ion transport initiated by Brian in collaboration with Guy Greville, and Brian had become interested in mechanisms. Peter arrived in an elegant if ancient Bentley convertible, and wrapped us in a corduroy enthusiasm. He was in trouble with his hypothesis, because three labs claimed to have disproved it by isolating the intermediates expected from the chemical hypothesis. Peter was undaunted, and engaged i n a mischievous discussion of the data and its validity. The challenge of the upstart chemiosmotic hypothesis to the prevailing chemical view of mechanism was to become a running battle, in which Peter engaged the establishment single-handed for several years before the first of a growing band of brothers (and sisters) joined him in the fray. The early work from Andr? Jagendorf's lab on H+-uptake and pH-jump driven ATP synthesis by chloroplasts, the parallel work on ion and metabolite transport in mitochondria from Chappell's lab, the work on ionophores and uncouplers by Bert Pressman, and by Brian Chappell and myself, the development of artificial membrane systems by Alec Bangham and by Paul Mueller, and Mitchell's own work with Jennifer Moyle on proton measurements following O2 pulses, had demonstrated before 1965 the activities expected from the hypothesis, but it was to be ten years before the established leaders in the field were coaxed into a grudging acceptance of the hypothe sis. The bones of the chemiosmotic hypothesis were fleshed out by Mitchell in subsequent publications, most notably the two slim volumes published by Glynn Research Ltd. in 1966 and 1968, known affectionately in the laboratory as

Free Essays on Debbie Style

As the world grows so do our challenges. Not only are our problems growing in number but they are also growing in complexity. There is scarcely a day that goes by when I don't hear about some new problem that will soon threaten us all. While some of these problems such as El Nino, earthquakes, and other natural disasters cannot be stopped there are other challenges such as the spread of racial hatred, rising risk of disease spread, and the growing levels of civil unrest throughout much of the world which threaten many lives everyday. Most of the future's challenges will only be made possible if all people, regardless of race, color, or nationality, attempt to work together for a stronger world. There are many ways in which I believe that I can help society meet this future challenge of coming together as a united world. While I was an exchange student, I saw the world from a different point of view. For the first time, I realized that the people of the world have so many similarities in comparison to the few and insignificant differences. To make the people of the world unite would merely take time in convincing people of the world that we are all in pursuit of the same basic goals. All that it would take to show that this could be done is two different cultures to unite and then the rest of the world what can come by the strength all gain by coming together. I believe that I can help in solving some of the barriers that hold us back from completing the task that we all desire which is unity. I served as a miniature version of a diplomat when I was an exchange student. I helped people in another country see that we all have common goals and I also helped sever the bonds to racial hatred by providing them insight into the American way of thinking and they did likewise for me. I have done everything to help sever these ancient bonds and will continue to do so in the future as I feel I am ca... Free Essays on Debbie Style Free Essays on Debbie Style As the world grows so do our challenges. Not only are our problems growing in number but they are also growing in complexity. There is scarcely a day that goes by when I don't hear about some new problem that will soon threaten us all. While some of these problems such as El Nino, earthquakes, and other natural disasters cannot be stopped there are other challenges such as the spread of racial hatred, rising risk of disease spread, and the growing levels of civil unrest throughout much of the world which threaten many lives everyday. Most of the future's challenges will only be made possible if all people, regardless of race, color, or nationality, attempt to work together for a stronger world. There are many ways in which I believe that I can help society meet this future challenge of coming together as a united world. While I was an exchange student, I saw the world from a different point of view. For the first time, I realized that the people of the world have so many similarities in comparison to the few and insignificant differences. To make the people of the world unite would merely take time in convincing people of the world that we are all in pursuit of the same basic goals. All that it would take to show that this could be done is two different cultures to unite and then the rest of the world what can come by the strength all gain by coming together. I believe that I can help in solving some of the barriers that hold us back from completing the task that we all desire which is unity. I served as a miniature version of a diplomat when I was an exchange student. I helped people in another country see that we all have common goals and I also helped sever the bonds to racial hatred by providing them insight into the American way of thinking and they did likewise for me. I have done everything to help sever these ancient bonds and will continue to do so in the future as I feel I am ca...

Irigaray an Essentialist or not Essay Example | Topics and Well Written Essays - 500 words

Irigaray an Essentialist or not - Essay Example She observes that women have been traditionally excluded from history of philosophy and psychoanalytic theories, only being related to other categories of the nature and matter instead. This denies women an opportunity to gain their own female subject position, which is distinguishable from the aspects of nature and matter (Fuss, 63). According to her, in the concept of philosophy, psychoanalytic theory and linguistic structure, a separate female position and identity does not exist, and thus women only gain subjectivity, when being associated with men. It is on the basis of this fact that she advocates for the concept of mimesis, which allows the members of a social group to come together, despite their differences, to take the advantage of the similarity that they exude, and forge a common identity, which would allow them to achieve certain goals (Fuss, 58). This advocacy requires women to take the advantage of the femininity, and forge an identity that they apply to push for recog nition and advocate for their rights, whenever they feel that such rights are not easily granted. Through the observation that women has no distinct subject position from that of nature and matter, Irigaray goes further to subject the stereotypes that are often given about women to scrutiny, to analyze such subjective views and put them into perspective (Fuss, 64). This is perceived through the lens of philosophy history and language. She upholds that women are not subjected to real views of themselves, and thus they should apply the views they are subjected to, to deny the stereotypes and show their true position. Therefore, if women are stereotyped to be illogical, then they should speak and act logically, so that they can disapprove that notion (Fuss, 71). She holds the view that negative prejudices and views against women cannot be overcome by merely ignoring the views, rather through confronting and demystifying the views in a more

Undersea Release of Methane Is Under Way Article Critique Essay

Undersea Release of Methane Is Under Way Article Critique - Essay Example Cornelia Dean has used an important subject of science for this article. Global warming is an issue of concern for the entire world and Dean has explained the new atmospheric changes that can worsen the situation and promote further warming of the environment. The article has been supported by the research work which has been carried out by different countries including Britain, Germany and the United States. This highlights the fact that the subject is essential for all the countries across the globe and scientists are working towards checking for the climatic changes of the world. The article portrays a new research which must be new to a large group of readers. Many people would be unaware with regard to the fact that undersea release of methane could be an ongoing process. The author has written the article in a very understandable way and the writer has provided evidence from different studies. Thus, the article is readable by the common man and it will be of further assistance to the people possessing scientific knowledge. Â  It also serves to explain the subject in a complete manner by providing a proper history of the release of methane gas into the atmosphere followed by the negative effects of increased amounts of the gas in the atmosphere. The article explains the entire global climatic situation which results from the release of methane gas into the atmosphere. It highlights the fact that the increase in methane gas in the atmosphere occurred following the era of industrialization.... He also explained that the release of methane from under the sea bed was not in great amounts but this situation could take a different turn. Cornelia Dean has used an important subject of science for this article. Global warming is an issue of concern for the entire world and Dean has explained the new atmospheric changes that can worsen the situation and promote further warming of the environment. The article has been supported by the research work which has been carried out by different countries including Britain, Germany and the United States. This highlights the fact that the subject is essential for all the countries across the globe and scientists are working towards checking for the climatic changes of the world. The article portrays a new research which must be new to a large group of readers. Many people would be unaware with regard to the fact that undersea release of methane could be an ongoing process. The author has written the article in a very understandable way and the writer has provided evidence from different studies. Thus, the article is readable by the common man and it will be of further assistance to the people possessing scientific knowledge. It also serves to explain the subject in a complete manner by providing a proper history of the release of methane gas into the atmosphere followed by the negative effects of increased amounts of the gas in the atmosphere. The article explains the entire global climatic situation which results from the release of methane gas into the atmosphere. It highlights the fact that the increase in methane gas in the atmosphere occurred following the era of industrialization and it continued to increase owing to the activities of man which include agricultural activities as well

Business Research Ethics Essay Example for Free

Business Research Ethics Essay The accounting world is changing constantly and so are the rules that are being set up to protect companies and their assets. There are codes of conduct that accounting offices and their personnel must adhere to and when they are not followed, there can be an ethical challenges that you have to deal with. Users of accounting information perform different types of creative accounting. Some of these practices are ethical and legal and other are not. It is important for a company to set up procedures that check and double check everyone in the accounting department from the clerks to the Controller. There is never a time in any business that someone is allowed to do things without having someone else check on their work. When there is no follow up or checks set in place is when the company finds themselves in trouble. As accountants, we are required to make sure that the work that we produce is accurate, credible and true information. This information is used to help investors and banks to make a good business decision in regard to their credit and investment opportunities. Many times, an accountant will get â€Å"creative† with the numbers to assure just that outcome. The numbers are inflated to show a better financial picture and this will help the company get more money and have the bank invest more in their future. Sometimes, this can go on for a long time without anyone knowing it is all false. Other times, companies get caught. May I remind you of Enron? Over the years stockholders and investors have lost large amounts of money due to false reporting or â€Å"creative† accounting. It is for this reason that the need for restrictions on those practices and find a solution to this problem became necessary. A company that I worked for in the past had to eventually file for bankruptcy because the Executive Board was unaware of what the Controller was doing. Many of us were aware of the incorrect numbers and were not sure how to handle it because we could not really prove that the numbers that he was  reporting were actually wrong. There are procedures in effect that prevent accountants from doing this, but not all companies follow them. This is why auditors are used with many companies. Auditors are there to make sure that all numbers and documents are proven to be correct and that there is no creative accounting or inflated numbers when looking at financial statements. Auditors can also be a deterrent for theft. If there is never a check and balance with an accountant in a company, there can be a greater chance of theft. I know of a company that I worked for suffered a loss of over $50,000 because the Controller was not required to get a second signature on checks under $5,000, so he issued himself eleven checks in the amount of $4,000. He would take the check and record that the check went to a vendor or supplier. When the bank statement was sent to our office, he would do the bank reconciliation, so no one saw the actual cancelled check because he destroyed it. Had there been an auditor that would be checking his work, this never would have continued to happen, they would have found it after the first check. It is important accountants to maintain integrity and avoid questionable situations. There are many things that can be seen as inappropriate. Many times over the years, I have been offered tickets to baseball games, dinners, gift baskets, etc. to use a particular company as a major supplier or to use a certain bank. I never thought much of accepting a gift basket, but I was told by an auditor for our firm that can be misunderstood and never to do that. This is a small scale, many companies have been known to get government contracts or big jobs because of making certain promises. Research has proven to our executives and investors that the only way to make sure that there is no inappropriate behavior by having internal and external auditors to examine the books on a regular basis. Knowing that there are audits completed on a random basis and knowing that those audits are being audited by external companies prevents mishaps, theft and misappropriation of funds. Having a clear set of policies and procedures in place and also having a clear plan of action for employees that do not follow these procedures is a sure way to insure that your company is protected. GAAP (generally accepted accounting practices) defines what is and is not permissible, but it is not infallible. GAAP can be manipulated and subject to interpretation and accountants can commit fraud any time. Eventually, we have to count on good accounting  procedures, our auditors and most importantly, employee ethics and morals to keep everything and everyone in line. REFERENCES Al Momani, M. A., Obeidat, M. I. (2013). The effect of auditors ethics on their detection of creative accounting practices: A field study. International Journal of Business and Management, 8(13), 118-136. Retrieved from http://search.proquest.com/docview/1418426106?accountid=458 Leung, E. C. (2004). Accounting ethics. Business and Society, 43(2), 226-226+. Retrieved from http://search.proquest.com/docview/199387513?accountid=458

The Genocide of the Chiricahua Indian Tribe Essay -- Apache Indians Na

The Genocide of the Chiricahua Indian Tribe United States history is taught in public schools from the time we are able to understand its importance. Teachings of honorable plights by our forefathers to establish this great nation are common. However, specific details of this establishment seem to slip through the cracks of our educational curriculum. Genocide by definition is the deliberate and systematic destruction of a racial, political or cultural group. The Chiricahua Indian Tribe of the American southwest and northern Mexico suffered almost complete annihilation at the hands of the American policy makers of the late nineteenth century, policy makers that chose to justify their means by ignoring their own tyrannical ways. It has been discovered that Apaches in the late 1800s were reported to exist in four separate bands, or clusters of rancherias, although how far back in time the division occurs is unknown (Griffen 5). The native name for the easternmost band was the Chihene, or "red painted people"; they were also known as Victorio, Mangas Coloradas, and Loco Apaches after the Spanish names of important leaders. To the south and west were the Chokonen or "Rising Sun People". These people were often called Central Chiricahua, True Chiricahua, and Cochise Apaches. North and west of the Chokonen were the Bedonkohe, "In Front at the End People" sometimes called the Geronimo Apaches. The southernmost Chiricahua band was the Ndeinda, "enemy people". They were also called the Nedni and Nednai, Southern Chiricahua, Pinery, and Bronco Apaches (Cole 10). These names differ among some scholars, but the majority of them can agree consistently on at least four bands, even if the names are different. Apache history is rich in custom, tradition, and worship of an all powerful supernatural force known as "The Power". Although accounts are different, after the creation of the world, "White Painted Woman" was created by Ussen. This supernatural female was the most important figure in Chiricahua religious belief. She was at once the progenitor of the Chiricahua people, the symbol of female activity and life, and the sponsor of all that was peaceful and gentle in human relationships. According to Chiricahuas, it was White Painted Woman who befriended the G’an, thus winning the sponsorship of the Apaches in a world filled with dangerous forces. ... ...ught more widely in American public schools to better understand how the southwest was and how it became to be. Tyranny in American history would be too controversial for the majority of the population; easier dealt with by not addressing it. It is also true that accounts of what actually happened differ among many scholars. Since the Apaches do not like to speak of the dead, their side of the story is difficult to obtain, and many American officers of the Army are too quick to gain recognition for things they did concerning the Chiricahuas. Finally, it is important to point out that it was the white man that invaded the Indian territory. The pride of the Chiricahuas would not allow this to happen, even though they knew their defeat was inevitable; it was Apache way. Works Cited Cole, D.C. The Chiricahua Apache 1846-1876: From War to Reservation. New Mexico: University of New Mexico Press,1988. Griffen, William B. Apaches at War and Peace: The Janos Presidio 1750-1858. New Mexico: University of New Mexico Press, 1988. Sweeney, Edwin R. Cochise: Chiricahua Apache Chief. Norman: University of Oklahoma Press, Publishing Division of the University, 1991.

Hydrofracking Global Issue

Hydro fracking's global impact Benefits Immediate solution to the energy crisis in the future Fracking is a solution to an affordable energy supply to the world                UK's future energy crisis due to low gas storage and rely heavy on import. Exploring the hidden potential for natural gas around the world                Many countries such as China, Australia, France, etc. have vast shale formation and potential for hydro-fracking natural gas. China has estimate 1,275 trillion cubic feet of technically recoverable gas compared to 862 trillion cubic feet in USLower energy costs for other countries around the world                               High cost from buying shipping energy from other countries                High costs to build nuclear plans for energy Global environment will benefit from hydro-fracking Solution to deal with global warning               Ã‚                  Carbon dioxin emission decr ease as the US's emission decrease 7. 7% since 2006               Ã‚  Importing energy through pipeline cause environmental damage due to methane leakage during transit Less toxic compared to nuclear plansJapan's nuclear shut down after tsunami disaster due to the toxic effect to the environment and people around the areas Benefit the countries's economies as wellas the world's economy                Partnership between China and the U,S create more jobs and stimulate the economy in both countries Drawbacks Global environmental's negative change Shale gas extraction cause earth tremors: possible earthquake but not strong and serious and only around the extraction area. Long-term risk for the underground water resources that might cause public ealth risks Political issue Many countries has not tapped the natural energy resource due to technical hurdle and political issue due to the danger that hydro fracking can cause to the people live near the s          à ‚                    France has strong public opposition to hydro-fracking                              Bulgaria ban it Poland welcome it but was charge with bribery during the awarding lease processing   and taint the plans                              Pending environmental review in South AfricaHigh costs for different countries In some European countries such as Poland, the costs to drill is three times more expensive compared to Texas, US. Need of Advance technologies to reduce drilling and extracting costs Geologies's differences issue China's shale formation are deeper underground, thus private property rights has hindered the development. The country's biggest shale gas prize lay in the province that water is hard to come by.