Types of macromolecules

As already stressed in the Introduction to this article, the use of organic plastics as biomaterials is expected to evolve in a natural way towards the utilization of increasingly higher quantities of inorganic polymers, because of the limitations inherently present in the first class of materials which seem to be absent or reduced in the second type of macromolecules. 

On this basis, five classes of different polyphosphazenes are considered as outstanding examples of this type of macromolecules, in which skeletal and substituent features overlap to the highest extent. The reported materials are elastomers, flame retardants and self-extinguishing macromolecules, polymeric ionic conductors, biomaterials, and photosensitive polymeric compounds all of them based on the polyphosphazene structure. 

Metallophosphazenes are a new type of macromolecule designed to bridge the gap between polymers and metals. Although still at an exploratory stage of laboratory development, they may provide access to electronically-conducting polymers, magnetically-active polymers, macromolecular catalysts, electrode mediator systems, or polymers crosslinked by metal atoms. 

I have reported so far only on one non-specific adsorption, that of random coils. Thus, ordered monolayers of polymers were rare and randomly packed first layers the rule. There are of course many other types of macromolecules and their adsorption, and an... 

Nucleic acid Either of two types of macromolecule (DNA or RNA) formed by polymerization of nucleotides. Nudeic adds are found in all living cells and contain the information (genetic code) for the transfer of genetic information from one generation to the next. [NIH]... 

AEv can be determined from calorimetry for organic Hquids. Fven though it cannot be determined experimentally for macromolecules, the value for the solubiHty parameter can be calculated based on individual group contributions for nearly any type of macromolecules [80]. 

The lysosomes are the cell s stomach, serving to break down various cell components. For this purpose, they contain some 40 different types of hydrolases, which are capable of breaking down every type of macromolecule. The marker enzyme of lysosomes is acid phosphatase. The pH optimum of lysosomal enzymes is adjusted to the acid pH value and is also in the range of pH 5. At neutral pH, as in the cytoplasm, lysosomal enzymes only have low levels of activity. This appears to be a mechanism for protecting the cells from digesting themselves in case lysosomal enzymes enter the cytoplasm at any time. In plants and fungi, the cell vacuoles (see p. 43) have the function of lysosomes. 

Two systems of polymer nomenclature have been introduced - the source-based and the structure-based. The latter cannot be used for all types of macromolecule, e.g., statistieal copolymer molecules and polymer networks. lUPAC expresses no strong preference for the use of structure-based nomenclature versus source-based nomenclature, but for certain purposes one system of naming may be preferred to the other.. ... 

Quantitative characteristics of a macromolecule or an assembly of macromolecules, such as mass and mole fractions or percentages as well as the degrees of polymerization and molar masses, may be expressed by placing corresponding figures after the complete name. The order of citation is the same as for the monomer species in the name. Some characteristics cannot be defined for all types of macromolecules and assemblies dealt with in this document, e.g. molar mass of a network. 

This procedure has been developed for quantification of the three types of macromolecules in tissue extracts, where other hiomolecules are also present. Small dissolved amounts of DNA, RNA, or protein, especially when no material should be consumed and no interfering substances are in the solution, maybe estimated by UV photometry, but a discrimination between DNA and RNA is impossible by reading absorbencies (cf. Protocol 1.2.5). 

Thietes are easily polymerized to different types of macromolecules that often turn up as undesired by-products. The fused compound 149 is easily transformed into a thioacrolein (Eq. 70), which polymerizes to a glassy solid. ... 

Thermal Properties. A typical dsc thermogram of an HPL/PVA blend (Fig. 4) shows a single Tg and Tm (10). Differences in the shape of the melting endotherms of PVA(96), (88), and (75) can be attributed to different degrees of crystallinity in the three polymers. Changes in crystalline structure of polymer blends usually result from polymer-polymer interactions in the amorphous phase. Such interactions result in a reduction of crystallinity, thereby reducing the enthalphy of the phase change (16,17). The observed reductions in melt endotherm area of HPL blends with PVA (> 0) may therefore indicate the existence of polymer-polymer interactions between the two types of macromolecules. 

The site of action may be an enzyme, a pharmacological receptor, another type of macromolecule, or a cell organelle or structure. The interaction of the toxic compounds at the site of action may be reversible or irreversible. The interaction is, however, assumed to initiate a proportional response. If the interaction is reversible, it may be described as follows ... 

Except for water, most of the molecules found in the cell are lipids or macromolecules, which can be classified into four different categories lipids, carbohydrates, proteins, and nucleic acids. Each type of macromolecule possesses distinct chemical properties that suit it for the functions it serves in the cell. 

Cells are composed of small molecules, macromolecules, and organelles. The most prominent small molecule is water, which constitutes 70% of the cell by weight. Other small molecules are present only in quite small amounts they are precursors or breakdown products of macromolecules or coenzymes. There are four types of macromolecules lipids, carbohydrates, proteins, and nucleic acids. 

The shape of a conformation can be characterized by various manipulations of the principal moments. The asymmetry of any one of the conformations is characterized by the dimensionless ratios 1 > L lL > L /L2 > OJ34,35 Spherical symmetry requires L lL2 = Lh)l = 1. Averaging of the corresponding principal moments over all conformations permits discussion of the asymmetry of the population of conformations in terms of (L2)I(Li) and (L2)/(L2). Examples of these dimensionless ratios are presented in Table 1.2 for four types of macromolecules, unperturbed by long-range interactions. In none of the four cases do the conformations have spherical symmetry. 

Watanabe and Regen 81 reported the construction of ordered, dendritic multilayers (10) via a bridged, outer sphere —outer sphere mode of assembly (Figure 9.5) whereby the transition metal Pt was used as a connector moiety. Although amine-terminated PAMAM-type dendrimers 76 were employed for this particular example, this process could easily be extended to other types of macromolecules. 

Nobody knows what the first hypothetical cells and their precursor structures looked like. If one assumes that the first cells were already based on the three types of macromolecules that are so essential for the functioning of all contemporary cells - DNA, RNA, and proteins - then one has to admit that the first cells were already chemically very complex systems. As a logical consequence, it is assumed that protocells were simpler entities. 

Since lysosomes are involved in digesting a whole range of biological material, exemplified by the destruction of a whole bacterium with all its different types of macromolecules, it is not surprising to find that a large number of different hydrolases reside in lysosomes. These enzymes catalyze the breakdown of nucleic acids, proteins, cell wall carbohydrates, and phospholipid membranes (see Table 1.1). 

The presence of charge introduce complication on some type of macromolecules. Some polymers are strings of acid groups (as... 

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