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Introduction: Background Material
Published in Nassir H. Sabah, Neuromuscular Fundamentals, 2020
Chemical potential is chemical potential energy per particle, or per mole, associated with concentration, so that the negative of the gradient of this potential is the “force” that effectively drives the particles from regions of higher concentration to regions of lower concentration.
Membrane Transport
Published in Lelio G. Colombetti, Biological Transport of Radiotracers, 2020
where μo is the standard chemical potential, a the activity of the ion, z the charge, F the Faraday constant, p the pressure, and the partial molar volume.
Concepts of Potential Energy, Enthalpy, and Bond Energy Calculations
Published in Patrick E. McMahon, Rosemary F. McMahon, Bohdan B. Khomtchouk, Survival Guide to General Chemistry, 2019
Patrick E. McMahon, Rosemary F. McMahon, Bohdan B. Khomtchouk
Chemical potential energy stored in the electromagnetic force of chemical bonds can be converted to kinetic energy during a chemical reaction. For example, an explosion converts chemical bond potential energy to work, heat, (and light). Conversely, kinetic energy can be converted to chemical potential energy when it is consumed to form certain types of chemical bonds.
Design, synthesis, molecular modelling and antitumor evaluation of S-glucosylated rhodanines through topo II inhibition and DNA intercalation
Published in Journal of Enzyme Inhibition and Medicinal Chemistry, 2023
Ahmed I. Khodair, Fatimah M. Alzahrani, Mohamed K. Awad, Siham A. Al-Issa, Ghaferah H. Al-Hazmi, Mohamed S. Nafie
The DFT molecular modelling calculations were performed to study the effect of inserion the sugar moiety on the sulphur atom of the thiooxothiazolin-4-one on the inhibition efficiency of the investigated compounds for enzyme. The molecular structures of the investigated compounds 13a, 13b and 13c obtained from the calculations are shown in Figure 4. By comparing between the inhibition of 3a, 3b and 3c compounds with that of 13a, 13b and 13c compounds, the calculations showed that the presence of sugar moiety decreases the biological activity which is in a good agreement with the experimental observations. Surprisingly, the calculations showed that inhibitors 3a, 3 b, and 3c have the lower energies of LUMO (−0.090, −0.099, and −0.094 au, respectively) than that of 13a, 13b and 13c (−0.077, −0.096, and −0.071 au, respectively), which means that these compounds could react as electrophiles (electron acceptor) with enzyme, Table 1. Also, the decreasing the energy gap, ΔE, between HOMO-LUMO for compounds 3a, 3b, and 3c (0.146, 0.144, and 0.134 au, respectively), means that those inhibitors are probably more favourable for the reactivity towards the enzyme. The increasing of the chemical potential, electronegativity and mean increasing the reactivity of the molecule and accordingly increase the biological activity, which agrees well with the experimental observations (Table 1).
Protective mechanism of Wnt4 gene on Parkinson’s disease (PD) transgenic Drosophila
Published in International Journal of Neuroscience, 2019
Wei Wu, Yanyin Han, Xiaoli Fan, Qinghua Li, Li Sun
UAS-PINK1B9; MHC-GAL4 as PD transgenic Drosophila model is characterized by indirect flight muscle damage and mitochondrial dysfunction. Under transmission electron microscopy, the indirect flight muscles of Drosophila in the control group were neatly arranged, the mitochondria were normal in size and evenly distributed, as shown in Figure 2(a). The indirect flight muscles of the model group were disordered, the number decreased. The muscle fibers were broken, and the mitochondria was expanded and structurally disordered (Figure 2(b)). The main function of mitochondria is to produce ATP through oxidative phosphorylation. The ATP production in the normal group is (0.87 ± 0.08) mmol/L, while the PINK1B9 model group is (0. 27 ± 0.05) mmol/L, significantly reduced by about 70% (p < 0.001) (Figure 2(c)). The mitochondria stores the chemical potential energy in the mitochondrial inner membrane when energy is generated. On both sides of the inner membrane, the potential of mitochondrial membrane mainly reflects the change of mitochondrial autophagy. The ratio of 520/590 mm in the normal group is (0. 98 ± 0.12), the PINK1B9 model group was (0. 41 ± 0.07), which was significantly reduced by 50%, and the difference was statistically significant (p < 0.05). The results are shown in Figure 2(d).
Adsorption of polypropylene oxide-polyethylene oxide type surfactants at surfaces of pharmaceutical relevant materials: effect of surface energetics and surfactant structures
Published in Pharmaceutical Development and Technology, 2019
Jinjiang Li, Sneha Rudraraju, Songyan Zheng, Archana Jaiswal
Thermodynamically, considering the contribution of entropy to free energy for polymer adsorption, DeGennes derived a chemical potential expression as shown in Equation (3). trans are the degree of polymerization, length of a monomer, interaction energy, the thickness of the adsorbed layer, and the chemical potential for trans-motion (De Gennes 1976). In Equation (3), trans represents the contribution of entropy and chain trans-motion to chemical potential respectively, and the δ s (F-H interaction parameter) (Daoud et al. 2010). Therefore, for many polymers (depending on δ), the amount of the adsorbed is generally related to Lifshitz–Van der Waals interaction.