Using Technology to Study Cellular and Molecular Biology

The Five E’s Engage Explore Explain Elaborate Evaluate

Needed Terminology Angstrom Bacteriophage Bioinformatics Infectious agent Laser Magnetic field Micrograph Nanometer Pathogen Pathology Probe Radiofrequency radiation Rational drug design Resolution Scale Spectroscopy Striated muscle Synchrotron Target-based drug design Technology Wavelength X-ray X-ray diffraction

What is technology? ???? Technology is a body of knowledge used to create tools, develop skills, and extract or collect materials. It is also the application of science (the combination of the scientific method and material) to meet an objective or solve a problem. Scale is a way to represent the relationship between the actual size of an object and how that size is characterized, either numerically or visually.

General Information Molecular biology = hybrid discipline which uses concepts and techniques from physics, chemistry, and biology. Technology = people believe this is more about computers rather than about a way of adapting or a process for solving a problem. Structure and Function are interdependent of each other. This relationship is critical to understand normal cellular processes. Scale = how big or small is something. Depends on the point of reference.

Techniques in the study  Reciprocal relationship between technology and the process of science.  Technology improvements let scientist investigate items that were previously difficult or impossible to solve.  While scientific curiosity has also helped refine or develop new levels of technology.

Types of microscopes (3) Optical Microscopy – used glass lenses to focus and magnify light. Constructed around Can distinguish objects as small as 200 nanometers; this resolution limit dictated by wavelength of light.

Requires a high vacuum in which to form an electron beam and high voltage to control the beam. The electromagnetic lenses then focus the electron beam onto the specimen and viewing screen.

Scanning electron microscope (SEM) – provides information about the surface features of an object. The object’s appearance, texture, and detectable features within a resolution of several nanometers. Process first used in Sometimes used with cryo-electron microscopy (cryo-EM); specimens are rapidly frozen without formation of ice crystals. Then possible to construct two and three dimensional models of the sample.

Other microscopic techniques  Coherent anti-Stokes Raman scattering – directs two laser beams into a cell.  Fourier transform infrared microspectroscopy (FTIR) – combine microscopy with spectroscopy to provide chemical information about the sample. Samples can be analyzed wet, dry, in air, at room temperature, and at normal pressure. Limited for analysis of living specimens. Currently being developed for objective evaluations of pap smears.  Laser confocal microscopy – used for obtaining high-resolution images and 3D reconstructions of biological specimens. Being used for DNA transcription apparatus.

Scanning probe microscopes (SPM) – use a microscopic needle-like probe that is scanned across a surface; a 3D image is constructed. Has the ability to operate on a scale from micro- to nanometers; magnifies up to 10,000,000 times. Can measure thermal properties, friction, hardness, and extent of chemical binding. X-ray crystallography – Combination of chemistry, physics, and biology. Provides information about how proteins function in cells. Being used to design better medicines for treating serious diseases.

Nuclear magnetic resonance (NMR) spectroscopy This refers to the absorption of radiofrequency radiation by nuclei in a strong magnetic field. Absorption of energy causes the nuclei to realign in the higher-energy direction. The nuclei then emit radiation and return to a lower energy state. Advantage of NMR is that it can be applied to the study of movement at the molecular level. NMR is expected to play a major role within the Human Genome Project; providing foundation for a major initiative in structural biology. MRI’s are just a limited part of what a NMR can do.