The Characteristics of Biophysics
The characteristics of biophysics include the use of complex physical tools to understand biological problems. This includes an attitude of mind, recognizing that certain mathematical and quantitative modeling approaches work well in biology.
Biophysicists typically address problems similar to those in molecular biology, seeking to find the physical underpinnings of biological phenomena.
Structure and dynamics of biological molecules
Using the knowledge and tools of physics, biophysicists can study the structure and function of living things, from how nerve cells communicate to how plant cells convert sunlight into energy. This application of the principles of physics has allowed scientists to develop vaccines, create new imaging techniques such as MRI and CAT scans for diagnosing diseases, and work on creating biofuels from living organisms that can replace gasoline.
Biophysicists use techniques such as fluorescent imaging, electron microscopy, X-ray crystallography, NMR spectroscopy and atomic force microscopy to observe the dynamics of biological molecules at the nanoscale. They also utilize mathematical models to understand the forces and distances between these molecules.
Another important area of research in this field is environmental biophysics, which studies the flow of energy in ecosystems. This includes the flow of thermal energy, which is necessary for organisms to function properly. It also focuses on factors that can influence the availability of thermal energy in an environment, such as the presence of tree canopies and soil temperature.
Interactions between biomolecules
Biophysicists study the fundamental interactions between molecules that make up living systems. They explore the physical character of these cooperative interactions across a broad range of scales, from the atomic and molecular to the cellular, organismal, population, and ecosystem levels.
They try to understand how linear polymers of only 20 different amino acids can fold into proteins with precise three-dimensional structures and specific biological functions, or how an enormously long DNA molecule untwists and exactly replicates itself during cell division. They are also concerned with the mechanical properties of biological systems on length scales from nanometers to meters.
Another important area of biophysics is electrophysiology, the study of cells that generate or conduct electrical signals. This includes nerve cells, muscle cells, electrogenic cells (such as photogenic and electroreceptive) and the specialized cells that transform energy from the environment into electrical signals in the eye or the skin.
Biomolecules and their environment
Many of the processes biophysicists study are complex and involve multiple molecules, such as the binding of large and small subunits in a ribosome or the folding of a nascent protein. Biophysicists use a variety of analytical and experimental techniques to observe, model, and manipulate these systems. In doing so, they draw on knowledge and tools from many disciplines. For example, the concept of binding affinity derives from physical chemistry, as do equilibrium constants and rate theories.
The field of biophysics arose from the desire of physicists to explain biological phenomena using the laws of physics and chemistry. The X-rays used by Franklin, Wilkins and Crick to discover the double helix were an early example of this. It also allowed biologists to better understand how linear polymers of amino acids could fold into proteins with precise three-dimensional structures and specific functions. Furthermore, it enabled them to explain how crowded cellular environments could allow for highly-tuned molecular mechanisms.
Biomolecules in cells
Biomolecules are chemical substances created by living organisms that range in size from small molecules (metabolites) to huge molecules (protein and carbohydrates). They are essential for the structure and proper functioning of living cells and organisms. The presence or lack of specific biomolecules can cause cellular dysfunction and result in diseases. Biomolecules can be derived from living or nonliving sources.
The biomolecules found in a cell include organic compounds such as proteins, carbohydrates, nucleic acids, and lipids. They are largely created from smaller building blocks called monomers, which are consolidated artificially to form complex polymers.
The molecular interactions that occur between biomolecules in a living cell are very complex and highly dynamic. They often involve multiple complexes, which are short-lived and require high turnover rates. In addition, they are influenced by the environment in which they are located. Hence, they are difficult to study in vitro. However, recent techniques such as high-throughput screens have made it possible to identify these biomolecules and their interaction with each other.