Biological Fundamentals

In the course of tissue augmentation (hyperplasia), the tumour outgrows into the surrounding tissue. To grow further and satisfy the increased demand for nutrients, the tmnour requires the formation of new blood vessels (angiogenesis) (Fig. 5.120). [300] Eventually, cancer cells are released into the blood or lymph system and disseminated into other organs to establish secondary tumours (metastases). 

The growth of a single cancer cell into a fully-developed tumour can be disrupted by cytostatics at a number of development stages. Important intervention points, each targeted by one or several classes of cytostatics, are the replication of DNA (alkylating agents, platinum complexes), cell division (antitubulin 

While during the interphase of the cell cyde, DNA is replicated, in the mitotic phase (M-phase) the nuclear chromosomes are separated into two identical sets. The latter step lasts in humans for arormd one hour. 

Essential for cell division is the formation of the spindle apparatus (Fig. 5.121). [302] This consists of axonemes (Fig. 5.122), which are part of the cyto-skeleton, and which are, along with some other types of filaments, responsible for the mechanical stabihsation of the cell and its outer shape, for active movement of the cell as a whole, as well as for movements and transport within the cell. 

The building blocks of the axoneme are microtubules, which are tubeshaped protein filaments (Fig. 5.123 and Fig. 5.124). They consist of hehcally arranged, spherical proteins, a- and yS-tubulin, each of ca. 450 amino acids (co. 50 kDa) in size. Both form a heterodimer, to which two molecules of guanosine triphosphate (GTP) are bonded (Fig. 5.125). One GTP is tightly bonded and can be removed only by denaturation of the heterodimer the second GTP can easily be replaced, and is involved in the dynamic instability of the microtubule, which is explained further down. 

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Thomson RC, Ishaug SL, Mikos AG, Langer R (in press). In Meyers RA (Ed) Encyclopedia of Molecular Biology Fundamentals and Applications, VCH Publishers, New York... 

Most of the genetic information of bacteria is contained in a single structure of fixed DNA content, a giant circular DNA molecule that replicates semi-conservatively. The enzymatic reactions involved in the biologically fundamental processes of DNA biosynthesis and genetic recombination are being elucidated in studies with bacterial systems. 

The advances attained in the last decades in the knowledge of the biological fundamentals underlying animal cell culture have enabled significant improvements in cell culture processes in vitro. In this chapter, the mechanisms that determine cell proliferation and cell death are discussed. Aspects concerning the kinetics and the mathematical description of cell growth and cell death are dealt with in Chapter 8. 

Josephy PD, Paul Ortiz de Montellano. Molecular Toxicology. U.K. Oxford University Press, 1997. ISBN 01-9509-3402. Useful for understanding the biological fundamentals in the metabolism of drugs, the basis of toxicology. 

Garban Z (1998) Molecular Biology Fundamental and Applicative Problems. 3 edition, Ed. Eurobit Timisoara (In Romanian). 

The idea of supported SAMs on gold and the concept of chemically modified electrodes have naturally fused to produce a new field of interdiscipKnary researches as described here, which are based on chemical, physical, electrochemical, and biological fundamentals and techniques. In this section, we can reahze that such new researches stem from unique characteristics of SAMs on gold. These include the convenient techniques for preparation, not simple but relatively precise identification of structures like that of molecules themselves, relatively stable forms presenting functionalized organic surfaces, and the capability of variations in the backbone structures. 

Sahm, H. 1993. Biotechnology, Biological Fundamental. Vol. 1,2nd edition, Weinheim Wiley-VCH. 

Department of Biological Fundamentals, Division of Science of Biological Resources, The Graduate School of Science and Technology, Kobe University, Rokkodai, Nada, Kobe 657, Japan... 

The influence of electrical charges on surfaces is very important to their physical chemistry. The Coulombic interaction between charged colloids is responsible for a myriad of behaviors from the formation of opals to the stability of biological cells. Although this is a broad subject involving both practical application and fundamental physics and chemistry, we must limit our discussion to those areas having direct implications for surface science. 

Biological infonnation is also concerned witli tire analysis of biological messages and tlieir import. The fundamental premise of tire protein-folding problem section C2.14.2.2 is tliat tire full tliree-dimensional arrangement of tire protein molecule can be predicted, given only tire amino acid sequence, together witli tire solvent composition, temperature and pressure. One test of tire validity of tliis premise is to compare tire infonnation content of tire sequence witli tire infonnation contained in tire stmcture [169]. The fonner can be obtained from Shannon s fonnula ... 

Clearly, the next step is the handling of a molecule as a real object with a spatial extension in 3D space. Quite often this is also a mandatory step, because in most cases the 3D structure of a molecule is closely related to a large variety of physical, chemical, and biological properties. In addition, the fundamental importance of an unambiguous definition of stereochemistry becomes obvious, if the 3D structure of a molecule needs to be derived from its chemical graph. The moleofles of stereoisomeric compounds differ in their spatial features and often exhibit quite different properties. Therefore, stereochemical information should always be taken into ac-count if chiral atom centers are present in a chemical structure. 

The fundamental assumption of SAR and QSAR (Structure-Activity Relationships and Quantitative Structure-Activity Relationships) is that the activity of a compound is related to its structural and/or physicochemical properties. In a classic article Corwin Hansch formulated Eq. (15) as a linear frcc-cncrgy related model for the biological activity (e.g.. toxicity) of a group of congeneric chemicals [37, in which the inverse of C, the concentration effect of the toxicant, is related to a hy-drophobidty term, FI, an electronic term, a (the Hammett substituent constant). Stcric terms can be added to this equation (typically Taft s steric parameter, E,). 

The process of target identification analyzes a complex disease process by dissecting it into its fundamental components. This makes it possible to identify the one that is most integral to the manifestation of the disease. Target identification aims to understand the biological processes related to a disease, and to identify its mechanism and the structure of individual elements of the disease. Commonly these individual elements are receptors, enzymes, etc., which become the target of new drugs. 

I do not wish to go into further discussion of the only too well-known close interrelationship of chemistry and biology, which some these days like to call chemical biology instead of biological chemistry. The interface of chemistry and physics can be equally well called chemical physics or physical chemistry, depending on from which side one approaches the field. What is important to realize is that chemistry occupies a central role between physics and biology. Chemistry is a truly central, multifaceted science impacting in a fundamental way on other sciences, deriving as much as it contributes to them. 

The chemistry of carboxylic acids is the central theme of this chapter The impor tance of carboxylic acids is magnified when we realize that they are the parent com pounds of a large group of derivatives that includes acyl chlorides acid anhydrides esters and amides Those classes of compounds will be discussed m Chapter 20 Together this chapter and the next tell the story of some of the most fundamental struc tural types and functional group transformations m organic and biological chemistry... 

Many globular proteins are enzymes They accelerate the rates of chemical reactions m biological systems but the kinds of reactions that take place are the fundamental reactions of organic chemistry One way m which enzymes accelerate these reactions is by bringing reactive func tions together m the presence of catalytically active functions of the protein... 

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