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Biology of microbes
Published in Philip A. Geis, Cosmetic Microbiology, 2006
What is fascinating about these reactions is that they all converge into three similar and common catabolic pathways: glycolysis, the tricarboxylic acid cycle, and the electron transport chain. What is even more fascinating is that these pathways exist as amphibolic pathways. This means that they can function both ways: anabolically and catabolically. Most of the reactions in glycolysis and the tricarboxylic acid cycle are reversible. Thus the molecules produced along the pathways can also be used as precursors for synthesizing macromolecules needed by cells for growth and repair. A few irreversible catabolic steps use special enzymes to catalyze the reverse reaction (i.e., phosphofructokinase) in order to regulate whether the amphibolic pathway will function as a catalytic or an anabolic pathway.
Regulation of Mammalian Hexokinase Activity
Published in Rivka Beitner, Regulation of Carbohydrate Metabolism, 1985
In contrast to the type I isozyme, a notable feature of the type II hexokinase is its insensitivity to reversal of glucose-6-P inhibition by Pi. As pointed out by Katzen,22 type II hexokinase predominates in insulin-sensitive tissues such as skeletal muscle (Table 1), and the tissue content of this isozyme is highly influenced by nutritional or hormonal status.19,22,52,55,63,72,73 This clearly could not be tolerated by a tissue (e.g., the brain) which exhibited a continuing primary dependence on glucose as a substrate for energy metabolism, and thus survival, and it was suggested above (Section III.A) that the type II isozyme served to provide glucose-6-P that may be used for energy metabolism or alternatively, to support synthesis of energy storage forms (glycogen, lipids). Additional considerations, discussed below, suggest that the latter may be the major function of type II hexokinase. Thus, another way to look at this would be to say that the type I enzyme primarily serves a catabolic role while the type II hexokinase predominant in insulin-sensitive tissues is anabolic, or at least amphibolic, in function. Indeed, referring to insulin as “essentially an anabolic hormone,” Elbrink and Bihler1 have previously called attention to the fact that increase in insulin-stimulated glucose transport is normally associated with insulin-stimulated syntheses of energy reserves.
Ficus carica extract impregnated amphiphilic polymer scaffold for diabetic wound tissue regenerations
Published in Artificial Cells, Nanomedicine, and Biotechnology, 2021
Jia Feng, Yu Niu, Yi Zhang, Hong Zuo, Shujin Wang, Xufeng Liu
The physical phase of free scaffold and extract loaded scaffold was investigated using X-ray diffraction analysis, which helped provide useful information for the interaction of the biological fluid with tissue engineering materials [35,36]. The diffraction patterns at 22.66°, 24.02°, 26.22°, 37.7°, 38.8° and 48.93° observed correspond to xylitol molecules present in the PXAG [21] (Figure 4(a)). The peaks at 20.45°, 25.6° and 26.22° reveal l-glutamic acid compounds in PXAG copolymer [37]. The presence of adipic acid in PXAG is authenticated from the diffraction peak at 22.09° [38]. The XRD pattern from Figure 4(a) reveals the high crystalline nature of the prepared PXAG copolymer. Figure 4(b) shows that the pattern intensities of PXAG copolymer decreased due to the combination of hydrophobic nature PHB polymer and the slight shifting in the diffraction peaks confirms the existence of physical interaction between PXAG and PHB polymers. Finally, FFE loaded PXAG-PHP scaffold intensity of the patterns further decreased due to the extract's covering in the PXAG-PHP scaffold (Figure 4(c)). Wound tissue materials crystalline phase made of synthetic polymers, for example, amphibolic polymers, polyesters likewise have the mechanical resistance that obliges development of the influenced body part and can retain more exudate than thin-film dressing [39].
Polyunsaturated fatty acids and endocannabinoids in health and disease
Published in Nutritional Neuroscience, 2018
Hércules Rezende Freitas, Alinny Rosendo Isaac, Renato Malcher-Lopes, Bruno Lourenço Diaz, Isis Hara Trevenzoli, Ricardo Augusto De Melo Reis
Insulin, growth hormone, and its secondary mediator insulin-like growth factor-1 are essential during the development, survival, and maintenance of cellular functions, mainly by its involvement with transcription factors and regulatory complexes. Strictly regulated by amphibolic pathways, these factors are also responsible for one of the most well-preserved regulation processes of cellular senescence, corroborating with the strong relationship between energetic imbalance and longevity.281
Splicing deregulation, microRNA and notch aberrations: fighting the three-headed dog to overcome drug resistance in malignant mesothelioma
Published in Expert Review of Clinical Pharmacology, 2022
Dario P. Anobile, Giulia Montenovo, Camilla Pecoraro, Marika Franczak, Widad Ait Iddouch, Godefridus J Peters, Chiara Riganti, Elisa Giovannetti
Animal models and human studies have shown that asbestos fiber inhalation can lead to MMe, lung cancer, and pulmonary fibrosis [14]. Of note, asbestos can be classified into two groups: amphiboles and serpentine. The longer and thinner amphibolic fibers can penetrate deeper into the respiratory system [15] and increase the likelihood of neoplastic diseases [14].