Physical Principles: Energy—The Prime Observable
The idea of abstractions as practical simplifications of systems has been introduced because it is fundamentally useful in the scientist’s day-to-day laboratory experience. By using different levels of abstraction while making observations on a system of interest, we can invoke different techniques. We often find ways to imply information that might not otherwise be accessible to direct measurement. When we examine a system, we decide at what level our detailed knowledge of the system will be needed and choose an abstraction appropriate to that level of detail. Abstractions are like choosing the magnification on a microscope. Remember that abstractions are simplifications; they do not operate out of context. Abstractions are attempts to generalize about systems whose actual behavior may be different from that predicted by the abstraction. Detecting these gaps between real and predicted behavior is the role of experimental science. We can formulate an image of a natural system with its peaks and valleys (represented by functions); then, choosing an abstraction, we predict a behavior of the system. Then we measure and map out the behavior of the real system to see if the prediction is correct. This map of the natural system’s state space gives us the information we need to describe the system and predict its future action. Several of the most important maps we can construct for a biological system are maps of its energy at each point of the state space and of the forces acting at each of these points. These energy and force mappings are a unifying idea that is used in every level of abstraction. Developing a facility and comfort with describing a system in terms of its energy surfaces unifies and simplifies the practice of biophysical chemistry.
KeywordsState Space Potential Energy Surface Physical Principle Potential Energy Barrier Biophysical Chemistry
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