Biological macromolecules proteins

With these difficulties in mind, it is instructive to look at main biological macromolecules - proteins, DNA, and RNA - that have precise and specific structures. These polymers in living systems are responsible for functions, which are incomparably more complex and diverse than the functions that we... 

Protein Data Bank (http //www.rcsb.org/pdb), international repository of experimentally resolved stmctures of biological macromolecules (proteins, nucleic acids, viruses), including anotations. 

X-ray crystallographers have now determined the structures of approximately one hundred biological macromolecules — proteins, nucleic acids, and viruses — to atomic resolution. These investigations have demonstrated that, unlike synthetic polymers, the biological molecules have specific three-dimensional conformations. Indeed, all information required to specify the structure of a protein is contained in the sequence of amino acids, and therefore the structure is also implicit in the sequence of nucleotides in the DNA or RNA genome. Analysis of the structures has provided explanations of their biological functions, and has revealed that there are recurrent architectural themes in their de-sign (J, 2). 

SAXS studies by solutions of biological macromolecules (proteins)... 

The three most abundant biological macromolecules— proteins, nucleic acids, and polysaccharides—are all polymers composed of multiple covalently linked identical or nearly identical small molecules, or monomers (Figure 2-11). The covalent bonds between monomer molecules usually are formed by dehydration reactions in which a water molecule is lost ... 

The PDB [7] covers biological macromolecules (proteins and nucleic acids) for which crystallographic results have been directly deposited with the compilers. The database currently contains 655 entries. Applications software is not distributed with the PDB. However, the data bank has been recast in a variety of forms for search and retrieval purposes [8,9]. Many molecular modelling systems (both commercial and academic in origin) can also read the PDB format. The database is compiled at the Department of Chemistry, Brookhaven National Laboratory, Upton, New York 11973, USA. 

Figure 1.2 General structure of a cell showing the main compartments (organelles) into which the interior is partitioned. ALL ceLLs of aLL organisms are constructed from the main bioLogicaL macromoLecuLes proteins, carbohydrates, and nucleic acids together with macromolecular lipid structures that comprise the membranes, (illustration from Philip Harris Ltd, Weston Super Mare, UK).

The Protein Data Bank (PDB) [5] is a computerized archive for the three-dimensional structural data on biological macromolecules - proteins and nucleic acids. Each protein structure reported has an identifying code (IDCODE), a header record containing useful information on the protein such as the name and source of the protein and the resolution of the structure, together with a series of references to published articles on the protein. Data are included on the refinement methods used, such as the programs used, the R value, the number of Bragg reflections, the root-mean-square deviations of the bond lengths and... 

The special thing about biological macromolecules (proteins, RNA and DNA) is that they have biological functions to fulfill. You could say that proteins, or RNA, or DNA are not only molecules of a particular substance, but each of the molecules is also a device or a machine to do particular operations. In this sense it is more straightforward to talk about such polymers in the language used to describe robots. 

In the literature the cluster model terms is perhaps more frequently used. However, the term cluster should be reserved for designating the experimentally existing atomic aggregates. Prototype molecules are those molecular systems, which may or may not exist experimentally, but they are designed to represent a characteristic portion of an extended system, such as a biological macromolecule, protein, crystal etc. 

A Identify, describe the distinguishing features of, and give an example of a molecule in each of the four major classes of biological macromolecules proteins, carbohydrates, lipids, and nucleic acids. 

While studies of biological macromolecules (proteins and nucleic acids) [1, 2] and phospholipid vesicles [3-5] using fluorescence spectroscopy techniques are numerous and many reviews have already been published, much less attention has been paid to surfactant micelles [6-9], and fluorescence studies of block copolymer micelles are even scarcer [10-12] so far despite the fast growing number of publications on block copolymer self-assembly in the literature. 

The interactions of biological macromolecules (proteins) with silicic acid were observed in vitro and documented by Her." He described these interactions as follows Silicic acid precipitates gelatin. . and. . albumin combines with silicic acid. It was also reported that polyalcohols and sugars did not affect the solubility of silica, but glycine reduced its rate of dissolution. Thus it was known that macromolecules interact with silica in vivo as well as in vitro, but in an unknown fashion. 

Kratky and Porod proposed a model of chain with smooth curvatures to interpret the results of their work on biological macromolecules. Proteins and DNA are rigid macromolecules in which local interactions (hydrogen bonds) exist that were ignored by the previously described models (see Figure 5.13). 

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