STMFMs and Biomedical Applications

Nondestructive STM interactions with biological material have immense potential, assuming certain technical obstacles are overcome. Potential problems include the following 1. Biomolecules, cells, and tissues are not conductors. Electron tunneling through these materials, if it occurs, may be damaging. Nevertheless, several groups including IBM Zurich have succeeded in imaging biomaterials in air such as protein coated DNA and virus structures. The tunneling is thought to occur from tip onto...

Soup vs Mud Chicken vs

What is life Living organisms have certain properties that are nearly synonymous with the trait of being alive-organization, growth, reproduction, dynamic purposeful activities and (at least in higher organisms) intelligence and consciousness. Life forms that we have come to know are all based on the same type of genetic blueprints (DNA, RNA) and building blocks (proteins), suggesting a common ancestry. That ancestry, life's emergence, is generally viewed as a rearrangement of cosmic matter...

Microtubule Organizing Centers MTOC and Centrioles

MTOC and their chief components, centrioles, are the specific apparatus within living cells which trigger and guide reorganization of cytoplasm such as occurs during growth, generation of form and function (differentiation) and cell movement. The enigmatic MTOC determine where, when, and how these functions occur (Figure 5.11). MTOC (or centrosomes) contain centrioles and pericentriolar substance which facilitates tubulin assembly by somehow lowering Cc. Centrioles are the common structure in...

Coherent Excitations Frhlich

Protein conformational states can register dynamic biological information and control the real time functions of cytoplasm. The mechanisms of conformational regulation are not clearly understood, primarily because technology has not (quite) yet reached the nanoscale. Proteins are clearly vibrant, dynamic structures in physiological conditions. A variety of recent techniques (nuclear magnetic resonance, X-ray diffraction, fluorescence depolarization, infrared spectroscopy, Raman and Brillouin...

Prokaryote to Eukaryote Symbiotic Jump

Proliferation of prokaryotes literally changed the face of the earth. According to the Margulis Sagan scenario, collective teams of bacteria gathered nutrients, disposed of toxins, recycled organic matter by turning waste into food and stabilized the atmosphere. Prokaryotic bacteria produced ammonia which adjusted the acidity of oceans and lagoons and increased the earth's temperature through a greenhouse effect similar to that of carbon dioxide (which lets in more solar radiation than can...

The Nature of Cytoplasm

The nature of cytoplasm has been scientifically studied for at least a century and a half. That history was described by Beth Burnside (1974) in a landmark meeting devoted to the cytoskeleton at the New York Academy of Sciences. An early French observer of cellular material, Felix Du Jardin proposed in 1835 that all cells were composed of a motile material called sarcode that had both structural and contractile properties. In 1861, Austrian E. Brucke linked the mechanical and physiological...

The Cytoskeleton and Medicine

Defects related to microtubules are specifically linked to several human diseases. One example is immotile cilia syndrome (Afzelius, 1979) which is caused by altered dynein and results in an inability to expel secretions from the lungs, leading to recurrent bacterial infections. Another is developmental disability in infants which is caused by abnormal MT function induced by defective MAPs (Purpura, 1982). The cytoskeleton participates in the effects of various diseases (malignancy, Alzheimer's...

SolitonsDa vydo v

Important biological events involve spatial transfer of energy along protein molecules. One well known example is the contractile curling of myosin heads in muscle contraction, fueled by the hydrolysis of ATP molecules. These quanta of biological energy are equivalent to 0.43 electron volts, only 20 times greater than background energy and insufficient to excite molecular electronic states. Consequently, under usual conditions biological systems do not emit photons. This implied to Davydov 1977...

Intermediate Filaments

The major filamentous components of the cytoskeleton are MT, actin filaments, intermediate filaments IF , and a class of delicate interconnecting fibrils called the microtrabecular lattice MTL which will be described later in this chapter. Here the unknown members of the cytoskeleton, intermediate filaments are reviewed Lazarides, 1980 . Intermediate filaments represent the most nebulous and chemically variable subgroup among the cytoskeleton. Five classes of IF have been distinguished which...

The Microtrabecular Lattice MTL

New techniques in electron microscopy developed by Keith Porter and colleagues 1981 at the University of Colorado at Boulder have led to observation of an irregular three dimensional lattice of slender strands throughout the cytoplasm, interconnecting nearly everything in the cell. The interlinked filaments appear to suspend the various cell systems, organelles, and larger cytoskeletal elements such as microtubules and filaments with a matrix material continuous with the individual lattice...

Energy and Information in Microtubules

Direct support for the propagation of signals in MT has been generated by Vassilev, Kanazirska, and Tien 1985 who reconstituted bilayer membranes from brain lipids and studied their electrical excitability. They suspended membranes as parallel unconnected plane surfaces separated several millimeters apart in a buffer solution which contained depolymerized tubulin, GTP, and other physiological components. Each membrane was monitored electrically and baseline recording of the two membranes showed...