Cell organization

Unicellular Single celled organism, such as bacteria. 

Lloyd, C., ed., 1986. Cell organization. Trends in Biochemical Sciences 11 437-485. 

Rather early in the evolution of bacteriology it was noted that these single-celled organisms readily stain with organic dye molecules. An elaborate classification scheme can in fact be de-... 

The diverse group Protozoa consists of microscopic single-celled organisms. Of the various protozoan types, only Radiolaria and Dinoflagellata are known to contain luminous organisms (Harvey, 1952 Herring, 1978). 

In contemporary societies replete with various industries and automobiles, NO (NO, N02, and N03) has been recognized to be one of the important factors responsible for air pollution. Only two decades ago, NO was found to be an essential molecule that regulates cellular/molecular functions in mammals. NO is also enzymatically synthesized in nonmammals, invertebrates, and yeasts. Therefore, the origin of NO may date back to the birth of life arising from single cell organisms living around 3-billion years ago. 

Amebicides (drugs that kill amebas) are used to treat amebiasis caused by the parasite E. histolytica. An ameba is a one-celled organism found in soil and water. Examples of amebicides are listed in the Summary Drug Table Amebicides. 

Fig. 14.20). Magnesium occurs in seawater and as the mineral dolomite, CaCOyMgCO,. Calcium also occurs as CaCO in compressed deposits of the shells of ancient marine organisms and exoskeletons of tiny one-celled organisms these deposits include limestone, calcite, and chalk (a softer variety of calcium carbonate). 

The principal molecular constituent of thin filaments is actin. Actin has been highly conserved during the course of evolution and is present in all eukaryotes, including single-celled organisms such as yeasts. Actin was first extracted and purified from skeletal muscle, where it forms the thin filaments of sarcomeres. It also is the main contractile protein of smooth muscle. Refined techniques for the detection of small amounts of actin (e.g., immunofluorescence microscopy, gel electrophoresis, and EM cytochemistry) subsequently confirmed the presence of actin in a great variety of nonmuscle cells. Muscle and nonmuscle actins are encoded by different genes and are isoforms. 

To build their structures and to carry out the myriad biochemical reactions that take place within their cells, organisms need a source of energy. The needed energy is obtained via biochemical pathways driven either by sunlight or by energy contained in reduced chemical compounds. 

The simulation of events as complicated as the interaction of biological systems such as protein folding, cells, organs, and whole organisms requires... 

Applications Membranes create a boundary between different bulk gas or hquid mixtures. Different solutes and solvents flow through membranes at different rates. This enables the use of membranes in separation processes. Membrane processes can be operated at moderate temperatures for sensitive components (e.g., food, pharmaceuticals). Membrane processes also tend to have low relative capital and energy costs. Their modular format permits rehable scale-up and operation. This unit operation has seen widespread commercial adoption since the 1960s for component enrichment, depletion, or equilibration. Estimates of annual membrane module sales in 2005 are shown in Table 20-16. Applications of membranes for diagnostic and bench-scale use are not included. Natural biological systems widely employ membranes to isolate cells, organs, and nuclei. 

The results for bacterial whole-cell analysis described here establish the utility of MALDI-FTMS for mass spectral analysis of whole-cell bacteria and (potentially) more complex single-celled organisms. The use of MALDI-measured accurate mass values combined with mass defect plots is rapid, accurate, and simpler in sample preparation then conventional liquid chromatographic methods for bacterial lipid analysis. Intact cell MALDI-FTMS bacterial lipid characterization complements the use of proteomics profiling by mass spectrometry because it relies on accurate mass measurements of chemical species that are not subject to posttranslational modification or proteolytic degradation. 

Figure 8. Calculated neutron diffractogram for methane (CD4) confined phase at full loading (6 molecules by unit cell, organized in trimers chain) in AlP04-5 zeolite. To explain and to analyze the observed diffractogram modifications, the three different terms which compose the diffractogram have been explicitly calculated.

There is great interest in the electrical and optical properties of materials confined within small particles known as nanoparticles. These are materials made up of clusters (of atoms or molecules) that are small enough to have material properties very different from the bulk. Most of the atoms or molecules are near the surface and have different environments from those in the interior—indeed, the properties vary with the nanoparticle s actual size. These are key players in what is hoped to be the nanoscience revolution. There is still very active work to learn how to make nanoscale particles of defined size and composition, to measure their properties, and to understand how their special properties depend on particle size. One vision of this revolution includes the possibility of making tiny machines that can imitate many of the processes we see in single-cell organisms, that possess much of the information content of biological systems, and that have the ability to form tiny computer components and enable the design of much faster computers. However, like truisms of the past, nanoparticles are such an unknown area of chemical materials that predictions of their possible uses will evolve and expand rapidly in the future. 

Pharmacodynamic studies deal more specifically with how the drug brings about its characteristic effects. Emphasis in such studies is often placed upon how a drug interacts with a cell/organ type, the effects and side effects it induces, and observed dose-response curves. 

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