Macromolecular complexes, metabolic

When povidone-iodine is used as a rinsing solution in body cavities, absorption of the whole macromolecular complex is possible. The complex has a molecular weight of about 60 000 and cannot be eliminated by the kidneys or metabolically. It is filtered by the reticuloendothelial system (4,8,9). 

The lipids of human plasma are transported in macromolecular complexes termed lipoproteins. A number of metabolic disorders that involve elevations in levels of any of the lipoprotein species are thus termed hyperlipoproteinemias or hyperlipidemias. The term hyperlipemia denotes increased levels of triglycerides in plasma. 

The role of hemoproteins (not hemoglobin) as electron transport elements in metabolic pathways is less widely appreciated. In these systems, hemoproteins called cytochromes may be mobile in the intracellar medium transferring electrons between reactive sites or may be immobilized within membrane-bound macromolecular complexes. ... 

Lipoproteins are macromolecular complexes that transport lipids within the blood. The major lipids transported by lipoproteins are triglycerides, cholesterol (both esterified and unesterified), phospholipids and fat-soluble vitamins, especially vitamin E. Lipoproteins also consist of specialized proteins, called apolipoproteins. Apolipoproteins serve a variety of physiological functions in lipoprotein metabolism, including cofactors for enzymes, ligands for cell-surface receptors and structural proteins for lipoproteins [1]. 

Clausius s couplet summarizes the vast range of experience that is canonized in thermodynamics, a subject that hes at the heart of chemistry, biochemistry, and indeed to all of nature. The power of thermodynamics hes in its abihty to provide a quantitative measure of the energy changes that occur in physical, chemical, and biological processes. Chemical reactions of metabolism, the transport of material across cell membranes, the assembly of membranes, and the assembly of other types of macromolecular complexes all obey these laws. Nothing overrides the laws of thermodynamics they are the decrees of fate. 

Chelates with amino acids or low molecular peptides may be regarded either from the standpoint of the metal ion or from the ligand. Thus, amino acid absorption and especially the transport of metal ions are substantially facilitated. This has been elucidated for transition ions which are biochemically important but tend to form macromolecular aquo-hydroxo-complexes. These complexes have a molecular weight too high to be absorbed directly. If these metal ions are prevented from hydrolysis by complexing with low molecular weight peptides they can be much better transported to their metabolic site. 

Characterization of the keratinized cells by classical histological and biochemical approaches has been difficult because of the intractable nature of the tissue. Yet it is precisely these properties of mechanical strength, insolubility, macromolecular character, and lack of metabolic activity along with its ease of isolation which makes stratum corneum amenable to analysis by physical methods. The extreme complexity of composition, molecular structure, and organization of stratum corneum make interpretation of these macroscopic properties in terms of molecular structure and events dependent heavily on analogous studies of model synthetic polymer systems and the more thoroughly characterized, keratin-containing wool. 

In addition to prokaryotic PHA accumulation, low-molecular mass poly-hydroxybutyrate complexed to other macromolecular cell components like proteins or polyphosphates (cPHB) can be found in the tissue of eukaryotic organisms. cPHB classically occurs in low quantities in the organisms and does not serve as storage material not all of the details of its metabolic functions have been elucidated [9]. 

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