Читать книгу Biomolecules from Natural Sources - Группа авторов - Страница 37

The sequence of polymer building in the cells starts from the DNA and the protein. Life must be started by the existence of many biological and chemical forms including both DNA and protein which are highly complicated polymers, not only in their components, but also in their design and the large amount of information installed which gives one the code and the other the dynamicability. Proteins alone are inactive structures, but if other elements exist (e.g., ions, water, pH, etc.) the requrement that enable them to react as biologically active and dynamic macromolecules with high specific reaction are satisfied.

Accumulation of mutants causes change in the protein function. Mutants in the cell cycle, repairing or apoptosis genes might turn normal cells to cancer cells. One important example is DNA and the RNA polymerases. DNA is a long linear polymer; found in the nucleus of a eukaryotic cell or in the cytoplasm of the prokaryotic cells and formed from nucleotides and shaped like a double helix; associated with the transmission of genetic information. RNA is a single strand long linear polymer of nucleotides found in the nucleus but mainly in the cytoplasm of the eukaryotic cell. The polymerases which work on them are different. The polymers represent essential and vital parts of the cells such as the DNA, RNA and protein. Additionally, they can be used as storage components such as starch, polyhydroxyalkanoates, etc. They can also be used by the cell for different purposes, for example as a protective agent (e.g., alginate, gums, and resin).

Biopolymers are different from the synthetic polymers in two main ways in that they are produced by living cells (produced naturally) and that they can be used by their main producer or by related or different kinds of the living cells (naturally biodegradable: capable of being decomposed). Generally, they belong to the biological system and their polymeric structure, the polymerization steps, and their degradation is done through various enzymatic activities. In other words they are a globally essential part of the biological system, produced by it and also degraded through it. For that it is normal to find a polymer produced by a microbe and degraded by the same microbe. More simply, it is a polymer for us, but it is a food or a part of the cell’s different structures for their producer. Their presence is governed by the biological aspects [25, 26]. As they from the biological system, their elements in most cases (except structures like native foreign protein and the LPS) are compatible with the human immune system [25, 27–31]. In some instances they are named white or green to demonstrate their compatibility with the biological system or their safety to nature [8, 28, 32, 33].