Argument
On
page 67- 69 Ericsson explains that doing an activity repeatedly can induce an
abnormal state for cells in some physiological system, and then these
biochemical states will trigger the activation of dormant genes within the cell’s
DNA. Therefore, this frequent engagement in certain areas of practice
activities will induce physiological strain which will cause the biochemical
changes that stimulate growth and transformation of cells. Ultimately, there
will be improved adaptations of the physiological systems. Explain how Ericsson’s
conclusion is possible through your knowledge of gene regulation and of human
cells. Use section 6.3 in Campbell book and chapter 18 for references. Relate
to the biology themes of regulation,
evolution, and continuity and change in your response.
Kirk Chiu- krkpchiu@gmail.com
Regulation can be applied to gene expression and DNA changing through biochemical processes by control elements in the DNA. The Campbell textbook describes these control elements as, "segments of noncoding DNA that help regulate transcription by binding certain proteins" (359). These control elements regulate the DNA that is later translated into a protein. Different biochemical reactions, such as a hormone, change the pieces of DNA that are coded for. The control elements change with the presence of a hormone and the whole cell changes because of it. Another example of regulation is the response of histones in the nucleus to the environment. Shenk delineates that, "histones protect the DNA and keep it compact. They also serve as a mediator for gene expression, telling genes when to turn on and off" (159). Shenk describes these histone, which are proteins wrapped in chromatin. They can affect DNA transcription as Shenk explains where histones "turn on and off" different DNA sequences during transcription. This ability allows cells to adapt to new environments and regulates the cells ability to survive in a changing environment.
ReplyDeleteJosh LeVay (blevay@comcast.net)
The theme of evolution is shown in environmental stresses through practice. Shenk explains that practice is necessary to improving a person's skills: "Practice style is crucial. Ordinary practice...is not enough to get better. It takes a special kind of practice to force your mind and body into the kind of change necessary to improve" (66). Shenk makes clear that practice is not enough to cause physiological changes because the strain is too weak on your body to force a need to adapt. Thus, intense practice, much like Ted Williams and Mozart previously mentioned in Shenk's novel did, causes a need to change. It can be intense exercise, which may cause control elements to transcribe a protein that helps with cellular respiration or the uptake of glucose in a muscle cell to further aid cellular respiration. This relates back to the theme of regulation where the cell must adapt to survive and ultimately allow reproduction. Going from the cellular level to the body level, environmental strains cause changes at all levels. Furthermore, in a PNAS study of humans practicing to use an appropriate verb for each noun spoken, scientists found, "Practice produced a shift in activity from left frontal, anterior cingulate, and right cerebellar hemisphere to activity in Sylvian-insular cortex" (Petersen). This study shows how studying even a simple concept with intense practice can lead to major physiological changes. In this case, the brain had the most change because the study focused on memorization and intelligence. The ability to adapt to environmental challenges enables an organism to survive and reproduce, which by natural selection allows a species to thrive.
ReplyDeleteFinally, continuity and change is shown by environmental stresses through the cell cycle and cancer. Continuity happens in response to environmental stimuli through mitosis. When a nearby cell dies, Campbell describes the process of mitosis as, "the division of the nucleus...Where there was one cell, there are now two, each the genetic equivalent of the parent" (230). Mitosis helps to recover from damage from the environment. A harmful change in the environment can be through carcinogens and high-radiation rays causing cancer. Campbell describes cancer when a cell is mutated, "the tumor grows and may eventually become malignant" (376). In this case the somatic cell has changed because of the harmful environment it was placed in. Another way in which change occurs from the environment occurs while developing as a fetus. Cells differentiate into different organs after organogenesis. Shenk describes the similarities between these body parts as having, "every brain cell and hair cell and heart cell in your body contain all of your DNA but still perform very specialized functions" (187). This explains how the environment affects cell structure and function. A cell in the heart has the continued DNA of a muscle cell, but performs very different functions because of the regulating factors in each cell.
http://www.pnas.org/content/95/3/853.full?sid=64a7ab80-300a-41ec-a417-162516358196
Josh LeVay (blevay@comcast.net)