ToK: Cellular Respiration

Peter Mitchell’s chemiosmotic theory encountered years of opposition before it was finally accepted. For what reasons does falsification not always result in an immediate acceptance of new theories or a paradigm shift? Please reflect on the aforementioned ToK questions.

17 thoughts on “ToK: Cellular Respiration

  1. Although there was significant evidence to back up Peter Mitchell’s theory on electron transport and proton movement, it was significantly different to the previous accepted theories. Therefore, it took time for the effects of the paradigm shift to ‘sink in’ as it is essentially binning what was known as a fact before. This level of uncertainty shakes scientists as science is known for its absolute answers.

  2. Peter Mitchell developed the chemiosmotic theory, which explained the mechanism by which mitochondria generate energy by converting ADP to ATP. Mitchell’s theory was originally met with skepticism however after years of opposition, it was finally scientifically accepted in the 1970s. Mitchell went on to win the 1978 Nobel Prize in chemistry for his chemiosmotic theory. This essay will explore the reasons why falsification of a theory does not always result in an immediate acceptance of a new theory.

    The scientific method involves first formulating a question, then devising a hypothesis, after this, tests, are carried out and the results either prove or disprove the hypothesis. Many philosophers believe that no amount of data can prove a theory, however the minutest of results can disprove one. This dictum is not entirely supported by the scientific world, as countless scientific theories are generally accepted despite the exceptions.

    Consequently, falsification in science has its limitations since majority of scientists do not abide by the rule that a theory has to be confirmed 100% in order for it to be accepted. Therefore falsification of a theory does not result in complete abandonment of that theory or even a paradigm shift. In fact, scientific theories are seldom deserted; instead, the theory is tweaked in order to salvage it.

    In conclusion, falsification of one theory does not pave the way for another theory to be automatically accepted. Instead, new theories must be validated on their own merits.

    1. Interesting response ,”Many philosophers believe that no amount of data can prove a theory, however the minutest of results can disprove one. This dictum is not entirely supported by the scientific world, as countless scientific theories are generally accepted despite the exceptions” can you think of a theory that has been accepted despite the exceptions?

  3. The reasons for falsification not always resulting in an immediate acceptance of new theories or a paradigm shift is because not many scientist follow the rule of discovering a theory and having that theory be completely confirmed. In addition to that, many theories are first received with scepticism so, in the end, it takes quite some work over years to allow scientists to find supporting evidence for their theories.

  4. Peter Mitchell, one of the most influential biologists during the 19th century, is well known for his investigation into mitochondrion and different enzymes involved in the conversion of ADP to ATP. To show how these enzymes’ arrangement affected the use of hydrogen ions as an energy source in the conversion, he presented the chemiosmotic theory, which inevitably met with years of opposition before he was awarded the Nobel Prize for Chemistry in 1978.
    A TOK question that arose from the following idea was, “To what extent do falsification play an effect in acceptance for new theories or paradigm shift?” Although Peter Mitchell’s chemiosmotic theory is familiar with us now, it was a revolutionary and radical proposal at those times. In the past, the prevalent idea was that energy of electron transfer is stored as a stable high-potential intermediate, kept to be conserved. A critical mistake of this theory was that there were no high energy intermediate ever discovered in mitochondrion, which slowly led to acceptance of the chemiosmotic theory. However, despite such apparent mistake to the older paradigm, theory stayed stable for long periods of time. Looking at this from a TOK perspective in terms of psychology, people tend to feel great fear from being separated form a familiar idea or “schema”. Although a new theory introduced a logically supported idea, it was one that could potentially revolutionize and debunk the entire basis of understanding the fundamental mechanisms of biological energy conservation. Therefore, great hesitation for community to move towards a novel theory may have been caused by fear of losing identity for an individual to connect with a community. Despite how old paradigm has been called as “falsification”, it had stayed as a respected theory for long periods of time; it had stayed as an influential source for contemporary biologists. By completely replacing the theory, it would have taken time to generalize the reason to the public, who had been placed under stagnation. A good example of this idea is Galileo’s observation to confirm Copernicus’ model of a heliocentric Solar System. This novel theory, like chemiosmotic theory, had initially encountered with opposition such as the Catholic Church. In this case, effect of religion had restricted falsification from immediately accepting new ideas to preserve the idea of Ptolemais cosmology, which acted as a basis to the “perfect and unchanging” belief of the followers of Catholic Church.
    As it can be seen from these examples, there are several reasons to why falsification cannot be immediately accepted with a novel idea, such as religion and reason. Observing from a psychological and religious perspective, it may be rare for immediate revolution to take place with old idea staying stable within the community. However, it is also inevitable for a falsification to go unnoticed, as truth always makes its appearance in the future.

    1. Could you elaborate on this statement: “Therefore, great hesitation for community to move towards a novel theory may have been caused by fear of losing identity for an individual to connect with a community”?

  5. Falsification is the act of falsifying, which is defined as “to make something false in order to make people believe that it is not true” ( In natural sciences, a scientific hypothesis is considered an idea until it has evident proof. After evidence supports the hypothesis, the idea becomes a theory and is acknowledged as an authorized justification for a phenomenon. Falsification does not always result in an immediate acceptance of new theories, as many other factors need to be considered. Peter Mitchell came up with the chemiosmosis theory, which encountered several years of falsifying before it was considered a scientific principle. One could say that falsifying a statement wont necessarily make it true as several other factors could affect the result which are not reflected on during the process of falsification.

  6. This essay will explore the reasons why falsification of a theory doesn’t always result in an immediate acceptance of a new theory. Primarily, cellular processes require energy (ATP). It has previously acknowledged that the hydrolysis of ATP to the di-phosphate (ADP) that is commonly needed for the biological reactions to take place.
    In 1961, a British biochemist called Peter Mitchell released a paper discussing the chemiosmotic theory, which discusses the mechanism of the generation of ATP through the electrochemical properties established in certain biological membranes (organelles). These are found in prokaryotes, and also eukaryotes through their mitochondria or chloroplasts. Mitchell’s ‘chemi-osmotic’ theory suggested that, rather than relying on energy-rich chemicals. They realized that oxidative phosphorylation (which is the synthesis of ATP from ADP occurring during respiration) was dependent on proton flow across membranes. Mitchell termed the ‘pull’ of protons back across the membrane as the ‘proton motive force’. This “flow of protons could be directed through protein-mediated channels for the purposes of performing useful work.” In his own words, from his 1961 ‘Nature’ paper he said that “the driving force on a given chemical reaction can be due to the spatially directed channeling of the diffusion of a chemical component or group along a pathway specified in space by the physical organization of the system”. Meaning that the structures can act as a basis for creating biochemical reactions in specific ways also known as ‘vectorial biochemistry’.
    His theory was then only approved in the 1970’s. And here is where the theory was falsified, this view was considered a drastic theory and faced a large resistance. It is has been identified over the years that no specific amount of data can prove a theory and the smallest doubt can disprove one. However, scientists over the years have gotten away with having their theories accepted even if they are not fully confirmed. This ultimately means that the theory doesn’t need to end up with a paradigm shift. In conclusion, the reason for falsification is not always due to the acceptance of theories as there are some scientists that follow the scientific method.

    1. “However, scientists over the years have gotten away with having their theories accepted even if they are not fully confirmed” When you say ‘fully confirmed’ what do you mean? Do you think there are some accepted theories that should not be accepted because they have not been ‘fully confirmed’?

  7. Science is deemed to be an area of knowledge that is solely based on reason as its way of knowing. This is based on the fact that science gains all its knowledge through the inductive process of the scientific method. This method includes observing a process, questioning it, and figuring out the rules that make the process work. When Peter Mitchell developed the theory of chemiosmosis in 1961, that defines the process of ATP synthesis as the conversion from ADP to ATP, he questioned the current theories due to their inconsistencies with what he observed. This was obviously met by the scientific community with disdain and disparagement. They were unwelcoming to his theory at first, and refused to adopt it. There were two main reasons.

    Firstly, in the world of science, theories are building blocks. They stack up on one another. When the theory of chemiostatsis was introduced this meant that a lot of the current theories that were based on the old invalid theory would begin to crumble. This meant that due to the fact that the old theory had pragmatic truth, and worked with all the other theories, it was regarded as correct. The theory consequently also had coherence truth to it as it jelled and worked well with the current infrastructure of science. So in a sense, the old theory even today could still be regarded as true due to the fact that it simply worked. Additionally, through the way of knowing emotion, the scientist of the times felt that the new theory was wrong as it questioned their personal theories and disregarded the current model. This was also seen during the introduction of our solar system model. When it was first introduced it was met with great opposition, mostly by the church, as they believed that earth was center of the universe and the skies consisted of several layers that eventually led to heaven. In this example the people of the time used faith as their way of knowing as their way of falsifying the new findings. This was due to the fact that pragmatically the old model for the solar system worked for their religious purposes. However, in endeavor for the truly true truth one must adopt an inductive method that allows for a basis of hypothesis on observations and changes in the knowledge base. This will allow the adoption of a correspondence truth that fit all the facts that being observed in reality. Due to the fact that Science is a cumulative effort, a paradigm shift does not just mean falsifying another man’s theory, but it also means a change in mindset. This change is hard to come by as mind set is based on emotion and faith, both of which are experientially learnt. This means that due to the fact that mindset is completely internalized, no amount of empirical proof will change it without the individual accepting the fact that sometimes just because something works in theory does not mean it works holistically.

    Secondly, even if the community had adopted an inductive method, their current theory would not have changed. This is due to the fact that in the nature of science when there are things that do not fit the current rules, the community disregards them as “exceptions”. An example of this would be the transition metals. In the natural science of chemistry, a group of metals on the periodic table is labeled as transition metals and the elements in this group share some unique qualities. One of the qualities they share is the ability to ionize in more than one form, for example iron can lose 4 or 5 electrons to become Iron4+ or Iron5+. Zinc, an element in this group, only has one ionization state. Zinc displayed all the other attributes of a transition metal, such as catalyzing reactions and forming colored compounds. It however missed a crucial quality; nevertheless, the scientific community considered it a transition metal due to its other properties. Contemporary research decades later proved its place in the transition metals by synthesizing Zinc with more than one ionization state. This example illustrates the ethos that the scientific community held. They would think of anomalies in data as expectations that will one day be explained or that it just doesn’t fit the rules; and that’s perfectly acceptable in science. For example all nonmetal don’t conduct electricity as solids, but graphite does. No one questions why, they just discover how and label it “exception”. This means that the introduction of new theories is difficult in the area of science, falsifying results just means that more “exceptions” are found. In science to establish a theory you must not try to prove it, as other processes could play a role in producing the results. You try to disprove your theory, and if you cannot then it is established. This can be seen in the example of a game, were the instructor says, “All blue cards have the number two on the back”. You are then presented with 3 cards, one showing a blue back, one showing the number two, and one with a red back. You are only allowed to flip one card to prove this hypothesis. Using inductive reasoning, you would flip over the red card to test your hypothesis; because flipping over the blue or the two or blue would just prove the theory, if you flip over the red and there is a two you falsify the theory. Conversely, some might say that you found an exception to the rule. In this same method, Mitchell’s results might have seen as proving his theory and not fully falsifying the current theory but only making exceptions. It would therefor be simpler for the scientific community to stick with their current theory and conclude Mitchell’s results as anomalies. A paradigm shift would mean a complete change in ideology, meaning what they currently regard as data that follows rules and trends, as false, and possibly even anomalies.

    So to conclude, as Max Planck once said, “A new scientific truth does not triumph by convincing its opponents and making them see the light, but rather its opponents eventually die, and a new generation grows up that is familiar with it.”. A paradigm shift in a single generation is almost impossible due to the pragmatic and correspondence truths it has with current theories and due to the nature of science. A change in paradigms is a change in ideology, and as the area of social sciences has proved multiple times (acceptance of colored people, equality), ideology is experientially developed, so a new paradigm simply means and requires fresh brains to develop on new more contemporary theories. A new generation has adopted the paradigm shift of Mitchell and as a result, his correspondence truth won him the Noble prize in chemistry in 1978.

    1. You said: “Science is deemed to be an area of knowledge that is solely based on reason as its way of knowing”, and you mentioned emotion – what about intuition? Do you think there are instances when scientist use their intuition and NOT reasoning to make advances in science?

  8. Falsification is the first step to a paradigm shift. Humans are always perusing ways of obtaining new information but not always are we willing to openly an immediately accept our findings. When investigating why falsification does not always immediately result in a paradigm shift, there are various reasons including: coming up with a new theory to replace it as well as the nature of humans and their unwillingness sometimes to accept change that can cause this.
    Falsification is purely finding something to not be true but longer measures must be taken to create a new theorem. This can be seen when after Newton’s Theory of Gravity had been accepted for centuries, but was then falsified by Einstein. Einstein’s Theory was unable to be accepted until its flaws had been eliminated. Only then once the flaws have been filtered out to ultimately reduce the need or change of a paradigm shift to take place can the new theory begin to be accepted. This therefore delays the acceptance of a new theory.
    Humans often are not willing to change what they were originally taught as a truth. This can stem from anything stemming from stubbornness to arrogance to fear as well as other possibilities. Fear could prevent immediate acceptance if for example, someone who lives in a suppressed community or one that was not accepting someone would fear the repercussions of their actions. This was a far bigger issue before the 21st century. Stubbornness and arrogance could interfere with the acceptance for various reasons due to the unpredictability of the nature of human emotions. Due to emotional reasons the wait for acceptance can be made longer until a paradigm shift is acceptance.
    In conclusion testing and human emotion can cause a new theory to be accepted immediately. There are cases where a paradigm shift can take place immediately. The majority of the time there is some sort of time period that is needed for such a change to take place. All of this depends on the specific situation and case.

  9. Falsification stands as the verification method of several scientific experimental conducts since it allows new theories to evolve as the original falsified concepts are being replaced. For a research hypothesis to hold weight it is suggested by philosopher ‘Karl Popper’ that the theory must be disprovable before it is considered conventional in the world of science.

    There could be many reasons as to why the ‘chemiosmotic theory’ wasn’t accepted directly. Firstly, science is no longer just based on basic theories but involves the graphing of different types of models to address for the same set of data. Once falsification is applied to such models, it is possible to alter the fit of the graphs to support one’s theory. The use of falsification to justify and verify the graph thus becomes too straightforward and less truthful.

    Secondly, Popper’s theory of falsification was heavily influenced by his involvement in the field of ‘Physics’. It is thus hard to generalize the similar theory to other scientific fields such as Biology and Chemistry. Every individual scientific experiment is based on a specific principle and thus its application of falsification is also different. For this reason falsification wasn’t immediately accepted in application to Mitchell’s theory.

    Lastly, Popper described the theory of falsification as a yes-or-no topic; that if the experiment is falsifiable it is scientific otherwise it’s not. However, this doesn’t take into account that some scientific researches are descriptive in nature and are aimed to further human knowledge and understanding rather than just testing a theory and then generalizing it.

    1. You say, “it is possible to alter the fit of the graphs to support one’s theory”, do you think this is a common practice? If so, what are the ramifications and how can we ensure that one’s theory isn’t just a set of altered data?

  10. What is a paradigm shift? It is a fundamental change in approach or underlying assumptions.

    Peter Mitchell’s chemiosmotic theory stated that essentially, most of the ATP synthesis in cells that are respiring, comes from the electrochemical gradient that is formed across the inner mitochondria membranes, that are formed from the breaking down of high energy molecules, like glucose (also known as glycolysis).

    Mitchell suggested this theory in 1961, and at the time, it was not very well accepted. At the time, the prevailing view was that the energy produced by the Electron transfer, was stored as a stable high potential intermediate. When Mitchell suggested his new theory, the ideas were new and strange, and people refused to believe it, thinking that their current view was stable and correct.

    But, there were also lots of unanswered question: Why were the enzymes of oxidative phosphorylation associated with the mitochondrial membrane? How did mitochondria maintain their osmotic balance? How did substrates get in and out? It was a lot of these small issues that Mitchell had addressed in his theory, and eventually the evidence for proton pumping in the electron transport chain started piling up, and people could no longer ignore it. This caused them to have a paradigm shift – to change their approach towards Mitchell’s theory. In 1978, Mitchell was awarded a Nobel Prize for Chemistry.

    So why does falsification of a theory not always result in an immediate acceptance of new theories or a paradigm shift? “Falsification” of something is the act of dismissing it as false information, without necessarily proving it wrong. According to Popper’s falsification principle, scientific theories are only correct until they are proven wrong. Popper said making mistakes is a very important part of gaining progress. A good scientific theory must be falsifyable. If it is “falsifyable”, that means a scientific experiment can be conducted to try and prove it wrong. In the process of doing this you may learn more about the subject than you already knew.

    Sometimes, people turn a small sample of information into a general theory. For example, going down to the lake, I can only see white swans, so I assume all swans are white. If someone told me there were black swans, I would not believe them. In Mitchell’s case, since he was going against the majority view, his theory was dismissed as a fraud. However, he had ample evidence to back it up, and in time this became glaringly apparent, and so people had to change their views and start accepting his.

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