The thought of molecular biology seemed incredibly daunting at first. I recall my first encounter with me sitting in my AP Biology class learning about virology. Studying viral behavior engrossed my attention as these infinitesimal beings were neither considered as living nor dead - they simply existed! I became curious as to how it would come to be. The following year took me to a college environment as a dual enrollment student surrounded by a sea of students in a General Chemistry 1 lab where colorful beakers of solvents and solutions cluttered the space.
I wanted to learn more about how biology and chemistry intertwined and were not separate entities in my future years of schooling. My first year at Pomona proved to be a year of exploration and challenges.
I always juggled between the thought of being a biology or a molecular biology major. I worked with Dr. Carol Kumamoto to explore the roles of two transcription factors, Czf1 and Sef1, that elicited an invasive filamentation response in the gastrointestinal yeast Candida albicans , which causes infections such as vaginitis and thrush.
Here I found that Sef1 might be significant in the expression of the CFL5 gene directly responsible for filamentation. It was an invigorating, yet intimidating experience. It was then when it clicked that I had to major in molecular biology. Over the course of my time at Pomona College, both in-person and virtually, majoring in molecular biology was one of the best decisions that I made. The small joys of assays going smoothly, all the way through finding significant data that leads to more questions are what makes it worthwhile.
Most importantly, it is the connections that are made with professors and classmates along the way that help build a solid foundation in my future career. Since I was little, I have always been enamored by science and attempting to understand how the body functions, one cell at a time. Our bodies are comprised of so many complex systems and interactions it would take centuries or millennia of research and experiments to understand every facet of ourselves.
Entering Pomona, I knew that I would major in either molecular biology or neuroscience. Unable to double major, I spoke with professors from both departments who guided me into choosing molecular biology as my major with a focus in neuroscience.
I love how this major provides a solid pathway to learn about molecular biology in the area of your choosing. No matter your focus, there are a variety of courses and electives that will satisfy your curiosity. The project involved creating a novel system to engineer homing endonucleases to cut DNA sequences of our choosing, allowing us to target genes in a similar fashion to CRISPR. To accomplish this, we modified an established system known as PACE to work with I-CREI, a homing endonuclease, to allow it to go through several hundred rounds of evolution.
Creating this system would be invaluable in the future of gene editing as it could provide an alternative to CRISPR and help provide solutions to genetic diseases such as sickle cell anemia. This research was extremely fascinating to learn about and develop, and through my time in the lab, I gained valuable techniques and the experience to troubleshoot and figure out solutions to problems in the lab.
I hope to come back to Pomona one day as a professor and guide future students on their path. I want to leave a positive impact on the lives of students and offer the same support, generosity and kindness that my professors have given me. I chose to major in molecular biology because it is the major that is most in line with my career goal of becoming a practicing physician.
I get to study how God designed life as we know it! This major allows students to interact with professors from both the Chemistry and Biology Departments! Not only that, but we get exclusive access to three academic buildings The professors in this department and the Chemistry department make it all worth it! They are amazing! Molecular biologists play an important role, not only in the scientific field but also …show more content… Diabetes is a disease in which the negative feedback loop that controls glucose level is broken.
However, in people with diabetes, this negative feedback loop is broken. When blood levels are too high, insulin is either not produced enough or the insulin receptor on cells that bind with insulin to open up the cell to glucose does not bind correctly, resulting in high levels of glucose in the bloodstream. The are two types of diabetes, type I and type II. The difference between the two is the cause and treatment for them.
Type II diabetes is caused by insulin resistance, in which insulin receptors no longer being able to bind with insulin to open up with the cell.
Molecular biologists not only research diseases and publish their findings, but they also advocate for specific diseases and health disparities within that disease to create awareness and support for the disease and the minority group. A health disparity that a molecular biologist might advocate for diabetes would be a disproportionate rate of diabetes in American Indians and Alaskan Natives. This means that American Indians and Alaskan Natives have more than double the chance of having diabetes than white Americans.
The disparity for American Indians and Alaskan Natives diabetics exists because of their accessibility to quality healthcare and relatively high poverty rate.. Show More. Read More. The Biopsychosocial Model Words 5 Pages Diabetes adds to this stress because residents voiced that the out of control sugar levels made them more stressed.
Oedema Case Studies Words 4 Pages Kidney size decreases, blood flow to the kidneys are effected and decreased the ability for the kidney to adsorb and secrete toxin for the circulatory system can be problematic, with the kidney not making enough concentration of urine this may increase the chances of the patient becoming dehydrated Seeley, Stephens and Tate Essay On Survival Of The Sickest Words 3 Pages The body is unable to recognize that the body has a sufficient amount of iron so the body continues to absorb iron from the food we as humans eat until it severely damages our body organs causing an imbalance in body chemistry which could ultimately lead to death if the hemochromatosis goes unchecked without any treatment.
Disparities In Health Care Case Study Words 2 Pages It being a long-term challenge among certain groups due to the disparities in health care in the united states. Essay On The Endocrine System Words 4 Pages The adrenals are known for making the hormone adrenaline but also, they make the corticosteroids which affect your metabolism and sexual function.
Bemp Case 8. Survival Of The Sickest Words 6 Pages With the support of insulin, glucose is stored in the liver, muscles, and fat cells. Sugar Nation Book Report Words 4 Pages For example, most doctors recommend increasing carbohydrate consumption and decreasing protein and fat.
Molecular biology is the branch of biology that studies the molecular basis of biological activity. Living things are made of chemicals just as non-living things are, so a molecular biologist studies how molecules interact with one another in living organisms to perform the functions of life.
The same basic process of gene expression transcription and translation The same molecular building blocks, such as amino acids. Molecular similarities provide evidence for the shared ancestry of life.
DNA sequence comparisons can show how different species are related. Fossils provide evidence of long-term evolutionary changes, documenting the past existence of species that are now extinct. Arguably, some of the best evidence of evolution comes from examining the molecules and DNA found in all living things. Also, conceptualizing DNA as an informational molecule see Section 2. Finally, the concept of the gene see Section 2.
Experimentation also figured prominently in the classical period see Section 3. Because of this, I have long felt that the future of molecular biology lies in the extension of research to other fields of biology, notably development and the nervous system.
Brenner, letter to Perutz, Along with Brenner, in the late s and early s, many of the leading molecular biologists from the classical period redirected their research agendas, utilizing the newly developed molecular techniques to investigate unsolved problems in other fields.
Francois Jacob, Jacques Monod and their colleagues used the bacteria Escherichia coli to investigate how environmental conditions impact gene expression and regulation Jacob and Monod ; discussed in Craver and Darden ; Morange Ch. The study of behavior and the nervous system also lured some molecular biologists. Finding appropriate model organisms that could be subjected to molecular genetic analyses proved challenging. And at Cambridge, Sydney Brenner developed the nematode worm, Caenorhabditis elegans , to study the nervous system, as well as the genetics of behavior Brenner , ; Ankeny ; Brown In subsequent decades, the study of cells was transformed from descriptive cytology into molecular cell biology Alberts et al.
Molecular evolution developed as a phylogenetic method for the comparison of DNA sequences and whole genomes; molecular systematics sought to research the evolution of the genetic code as well as the rates of that evolutionary process by comparing similarities and differences between molecules Dietrich ; see also the entries on evolution , heritability , and adaptationism. The immunological relationship between antibodies and antigens was recharacterized at the molecular level Podolsky and Tauber ; Schaffner ; see also the entry on the philosophy of immunology.
And the study of oncogenes in cancer research as well as the molecular bases of mental illness were examples of advances in molecular medicine Morange b; see also the entry on philosophy of psychiatry. The molecularization of many fields introduced a range of issues of interest to philosophers.
Inferences made about research on model organisms such as worms and flies raised questions about extrapolation see Section 3. And the reductive techniques of molecular biology raised questions about whether scientific investigations should always strive to reduce to lower and lower levels see Section 3.
In the s, as many of the leading molecular biologists were migrating into other fields, molecular biology itself was going genomic see the entry on genomics and postgenomics. The number of base pairs varies widely among species. For example, the infection-causing Haemophilus influenzae the first bacterial genome to be sequenced has roughly 1. The history of genomics is the history of the development and use of new experimental and computational methods for producing, storing, and interpreting such sequence data Ankeny ; Stevens Frederick Sanger played a seminal role in initiating such developments, creating influential DNA sequencing techniques in the s and s Saiki et al.
In the mid s, after the development of sequencing techniques, the United States Department of Energy DoE originated a project to sequence the human genome initially as part of a larger plan to determine the impact of radiation on the human genome induced by the Hiroshima and Nagasaki bombings. While the human genome project received most of the public attention, hundreds of genomes have been sequenced to date, including the cat Pontius et al.
One of the most shocking results of those sequencing projects was the total number of genes defined in this context as stretches of DNA that code for a protein product found in the genomes. The human genome contains 20, to 25, genes, the cat contains 20, genes, the mouse 24,, and rice 32, to 50, So in contrast to early assumptions stemming from the classical period of molecular biology about how genes produced proteins which in turn produced organisms, it turned out that neither organismal complexity nor even position on the food chain was predictive of gene-number see the entry on genomics and postgenomics.
And the human genome project itself has turned its attention from a standardized human genome to variation between genomes in the form of the Human Genome Diversity Initiative Gannett and the HapMap Project International HapMap Consortium A related challenge was making sense of the genetic similarity claims.
Does this finding tell us anything substantive about our overall similarity to pumpkins Piotrowska ? To help answer such questions, genomics is now supplemented by post-genomics. There is ongoing debate about what actually constitutes post-genomics Morange , but the general trend is a focus beyond the mere sequence of As, Cs, Ts, and Gs and instead on the complex, cellular mechanisms involved in generating such a variety of protein products from a relatively small number of protein-coding regions in the genome.
Post-genomics utilizes the sequence information provided by genomics but then situates it in an analysis of all the other entities and activities involved in the mechanisms of transcription transcriptomics , regulation regulomics , metabolism metabolomics , and expression proteomics.
Developments in genomics and post-genomics have sparked a number of philosophical questions about molecular biology. Since the genome requires a vast array of other mechanisms to facilitate the generation of a protein product, can DNA really be causally prioritized see Section 2.
Similarly, in the face of such interdependent mechanisms involved in transcription, regulation, and expression, can DNA alone be privileged as the bearer of hereditary information, or is information distributed across all such entities and activities see Section 2.
The concepts of mechanism , information , and gene all figured quite prominently in the history of molecular biology. Philosophers, in turn, have focused a great deal of attention on these concepts in order to understand how they have been, are, and should be used. Molecular biologists discover and explain by identifying and elucidating mechanisms, such as DNA replication, protein synthesis, and the myriad mechanisms of gene expression.
Discovering the mechanism that produces a phenomenon is an important accomplishment for several reasons. First, knowledge of a mechanism shows how something works: elucidated mechanisms provide understanding.
Second, knowing how a mechanism works allows predictions to be made based upon the regularity in mechanisms. For example, knowing how the mechanism of DNA base pairing works in one species allows one to make predictions about how it works in other species, even if conditions or inputs are changed.
Third, knowledge of mechanisms potentially allows one to intervene to change what the mechanism produces, to manipulate its parts to construct experimental tools, or to repair a broken, diseased mechanism. In short, knowledge of elucidated mechanisms provides understanding, prediction, and control. Given the general importance of mechanisms and the fact that mechanisms play such a central role in the field of molecular biology, it is not surprising that philosophers of biology pioneered analyzing the concept of mechanism see the entry on mechanisms in science.
Starting in the s, a number of philosophers focused squarely on how the concept of a mechanism functions in science generally and molecular biology specifically Glennan and Illari ; see also the entry on mechanisms in science.
A number of characterizations of what a mechanism is have emerged over the years Bechtel and Abrahamsen ; Glennan ; Machamer, Darden, and Craver Phyllis McKay Illari and Jon Williamson have more recently offered a characterization that draws on the essential features of all the earlier contributions:.
A mechanism for a phenomenon consists of entities and activities organized in such a way that they are responsible for the phenomenon. Illari and Williamson As an example, consider the phenomenon of DNA replication. It has not escaped our notice that the specific pairing we have postulated immediately suggests a possible copying mechanism for the genetic material.
In short, the double helix of DNA an entity with an organization unwinds an activity and new component parts entities bond an activity to both parts of the unwound DNA helix. DNA is a nucleic acid composed of several subparts: a sugar-phosphate backbone and nucleic acid bases. When DNA unwinds, the bases exhibit weak charges, properties that result from slight asymmetries in the molecules.
These weak charges allow a DNA base and its complement to engage in the activity of forming hydrogen weak polar chemical bonds; the specificity of this activity is due to the topological arrangements of the weak polar charges in the subparts of the base. Ultimately, entities with polar charges enable the activity of hydrogen bond formation. After the complementary bases align, then the backbone forms via stronger covalent bonding. The mechanism proceeds with unwinding and bonding together activities new parts, to produce two helices newly formed entities that are more or less faithfully copies of the parent helix.
Scientists rarely depict all the particular details when describing a mechanism; representations are usually schematic, often depicted in diagrams see the entry on models in science. A mechanism schema is a truncated abstract description of a mechanism that can be instantiated by filling it with more specific descriptions of component entities and activities.
This is a schematic representation with a high degree of abstraction of the mechanism of protein synthesis, which can be instantiated with details of DNA base sequence, complementary RNA sequence, and the corresponding order of amino acids in the protein produced by the more specific mechanism. Molecular biology textbooks are replete with diagrams of mechanism schemas. A mechanism schema can be instantiated to yield a description of a particular mechanism.
In contrast, a mechanism sketch cannot yet be instantiated; components are as yet unknown. Sketches have black boxes for missing components or grey boxes whose function is known but whose entities and activities that carry out that function are not yet elucidated. Such sketches guide new research to fill in the details Craver and Darden The language of information appears often in molecular biology.
Historians of biology have tracked the entrenchment of information-talk in molecular biology Kay since its introduction. The question for philosophers of biology is whether an analysis of the concept of information can capture the various ways in which the concept is used in molecular biology e.
Stephen Downes helpfully distinguishes three positions on the relation between information and the natural world:. These options may be read either ontologically or heuristically. A heuristic reading of 1 , for instance, views the talk of information in molecular biology as useful in providing a way of talking and in guiding research.
And so the heuristic benefit of the information concept can be defended without making any commitment to the ontological status Sarkar Indeed, one might argue that a vague and open-ended use of information is valuable for heuristic purposes, especially during early discovery phases in the development of a field.
Stegmann does explicitly allow that components other than nucleotide sequences might contain what he calls instructional information.
However, his only example is a thought experiment involving enzymes linearly ordered along a membrane; nothing of the sort is known to actually exist or even seems very likely to exist. Stegmann calls this the sequentialization view. On his account, DNA qualifies as an instructional information carrier for replication, transcription and translation. The sequence of bases provides the order.
The hydrogen bonding between specific bases and the genetic code provide the specific kinds of steps. And the mechanisms of replication, transcription, and translation yield certain outcomes: a copy of the DNA double helix, an mRNA, and a linear order of amino acids. For more on this topic, see the entry on biological information. She argues that information is ubiquitous. She defines information as follows: a source becomes an informational input when an interpreting receiver can react to the form of the source and variations in this form in a functional manner.
She claims a broad applicability of this definition. The definition, she says, accommodates information stemming from environmental cues as well as from evolved signals, and calls for a comparison between information-transmission in different types of inheritance systems — the genetic, the epigenetic, the behavioral, and the cultural-symbolic.
On this view, genes have no theoretically privileged informational status Jablonka Kenneth Waters argues that information is a useful term in rhetorical contexts, such as seeking funding for DNA sequencing by claiming that DNA carries information. As discussed in Section 2. Talk of information is not needed; causal role function talk is sufficient. The question of whether classical, Mendelian genetics could be or already has been reduced to molecular biology to be taken up in Section 3.
Investigations of reduction and scientific change raised the question of how the concept of the gene evolved over time, figuring prominently in C. Over time, however, philosophical discussions of the gene concept took on a life of their own, as philosophers raised questions independent of the reduction debate: What is a gene?
And, is there anything causally distinct about DNA? For a survey of gene concepts defended by philosophers, see Griffiths and Stotz , An example will help to distinguish the two: When one talked about the gene for cystic fibrosis, the most common genetic disease affecting populations of Western European descent, the Gene-P concept was being utilized; the concept referred to the ability to track the transmission of this gene from generation to generation as an instrumental predictor of cystic fibrosis, without being contingent on knowing the causal pathway between the particular sequence of DNA and the ultimate phenotypic disease.
The Gene-D concept, in contrast, referred instead to just one developmental resource i. A second philosophical approach for conceptualizing the gene involved rethinking a single, unified gene concept that captured the molecular-developmental complexities.
Returning to the case of cystic fibrosis, a PMG for an individual without the disease referred to one of a variety of transmembrane ion-channel templates along with all the epigenetic factors, i.
And so cystic fibrosis arose when a particular stretch of the DNA sequence was missing from this process. Relatedly, philosophers have also debated the causal distinctiveness of DNA. Consider again the case of cystic fibrosis. A stretch of DNA on chromosome 7 is involved in the process of gene expression, which generates or fails to generate the functional product that transports chloride ions.
But obviously that final product results from that stretch of DNA as well as all the other developmental resources involved in gene expression, be it in the expression of the functional protein or the dysfunctional one. Thus, a number of authors have argued for a causal parity thesis, wherein all developmental resources involved in the generation of a phenotype such as cystic fibrosis are treated as being on par Griffiths and Knight ; Robert ; Stotz Waters , see also his entry on molecular genetics , in reply, has argued that there is something causally distinctive about DNA.
Causes are often conceived of as being difference makers, in that a variable i. So RNA polymerase is a difference maker in the development or lack of development of cystic fibrosis, but only a potential difference maker, since variation in RNA polymerase does not play a role in the development or lack of development of cystic fibrosis in natural populations.
The stretch of DNA on chromosome 7, however, is an actual difference maker. That is, there are actual differences in natural human populations on this stretch of DNA, which lead to actual differences in developing or not developing cystic fibrosis; DNA is causally distinctive, according to Waters, because it is an actual difference maker.
Advocates of the parity thesis are thus challenged to identify the other resources in addition to DNA that are actual difference makers. Recently, Paul Griffiths and Karola Stotz have responded to this challenge by offering examples in which, depending on context, regulatory mechanisms can either contribute additional information to the gene products or create gene products for which there is no underlying sequence. Thus, according to Griffiths and Stotz, to assign a causally distinctive role to DNA, as Waters does, is to ignore key aspects of how the gene makes its product.
In addition to analyzing key concepts in the field, philosophers have employed case studies from molecular biology to address more general issues in the philosophy of science, such as reduction, explanation, extrapolation, and experimentation.
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