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1.
本文着重阐述了有机体能量代谢过程中ATP—CP系统、有氧氧化和无氧酵解三大供能系统的偶联反应。并对ATP恢复的影响因素作了分析,同时介绍了作者对ATP的再认识和理解。 相似文献
2.
A review of the literature suggests that the effects of nitric oxide (NO) on skeletal muscles fibers can be classified in
two groups. In the first, the effects of NO are direct, due to nitrosation or metal nitrosylation of target proteins: depression
of isometric force, shortening velocity of loaded or unloaded contractions, glycolysis and mitochondrial respiration. The
effect on calcium release channels varies, being inhibitory at low and stimulatory at high NO concentrations. The general
consequence of the direct effects of NO is to ‘brake’ the contraction and its associated metabolism. In the second group,
the effects of NO are mediated by cGMP: increase of the shortening velocity of loaded or unloaded contractions, maximal mechanical
power, initial rate of force development, frequency of tetanic fusion, glucose uptake, glycolysis and mitochondrial respiration;
decreases of half relaxation time of tetanus and twitch, twitch time-to-peak, force maintained during unfused tetanus and
of stimulus-associated calcium release. There is negligible effect on maximal force of isometric twitch and tetanus. The general
consequence of cGMP-mediated effects of NO is to improve mechanical and metabolic muscle power, similar to a transformation
of slow-twitch to fast-twitch muscle, an effect that we may summarize as a ‘slow-to-fast’ shift. 相似文献
3.
Flying insects: model systems in exercise physiology 总被引:1,自引:0,他引:1
G. Wegener 《Cellular and molecular life sciences : CMLS》1996,52(5):404-412
Insect flight is the most energy-demanding exercise known. It requires very effective coupling of adenosine triphosphate (ATP) hydrolysis and regeneration in the working flight muscles.31P nuclear magnetic resonance (NMR) spectroscopy of locust flight muscle in vivo has shown that flight causes only a small decrease in the content of ATP, whereas the free concentrations of inorganic phosphate (P
i
), adenosine diphosphate (ADP) and adenosine monophosphate (AMP) were estimated to increase by about 3-, 5- and 27-fold, respectively. These metabolites are potent activators of glycogen phosphorylase and phosphofructokinase (PFK). Activation of glycolysis by AMP and P
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is reinforced synergistically by fructose 2,6-bisphosphate (F2,6P2), a very potent activator of PFK. During prolonged flight locusts gradually change from using carbohydrate to lipids as their main fuel. This requires a decrease in glycolytic flux which is brought about, at least in part, by a marked decrease in the content of F2,6P2 in flight muscle (by 80% within 15 min of flight). The synthesis of F2,6P2 in flight muscle can be stimulated by the nervous system via the biogenic amine octopamine. Octopamine and F2,6P2 seem to be part of a mechanism to control the rate of carbohydrate oxidation in flight muscle and thus function in the metabolic integration of insect flight.Dedicated to Dr. Ernst Zebe, Emeritus Professor of Zoology (University of Münster) on the occasion of his 70th birthday. 相似文献
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6.
H. W. Hofer 《Cellular and molecular life sciences : CMLS》1996,52(5):449-454
The glycolytic control enzyme phosphofructokinase from the parasitic nematodeAscaris lumbricodies is regulated by reversible phosphorylation. The enzyme is phosphorylated by an atypical cyclic adenosine monophosphate (cAMP)-dependent protein kinase whose substrate specificity deviates from that of the mammalian protein kinase. This variation is explained by structural peculiarities on the surface part of the catalytic groove of the protein kinase. Also, the protein phosphatases responsible for the reversal of phosphorylation appear to act specifically in glycolysis and are different from those participating in regulation of glycogenolysis. 相似文献
7.
以一缩二乙二醇为醇解剂,在微型双螺杆共混仪中进行氨纶废丝的降解反应,通过测试降解产物的特性粘度描述了降解过程,并建立了相应的降解动力学方程,得到降解反应活化能E=115.87kJ/mol。 相似文献
8.
固体酸催化剂在醇解聚对苯二甲酸乙二醇酯反应中的催化性能 总被引:1,自引:0,他引:1
采用浸渍法制备了SO4^2-/ZnO和S^4^2-/TiO2固体酸催化剂,用XRD、SEM等对催化剂的晶型结构和表面形貌进行了表征,并考察了它们降解聚对苯二甲酸二乙二醇酯制备对苯二甲酸二乙二醇酯的催化性能.实验结果表明,焙烧温度对SO4^2-/ZnO的催化活性影响不大,而对SO4^2-/TiO2的催化活性影响明显,随焙烧温度的升高,其催化活性出现先上升后下降的趋势反应时间、反应温度、催化剂浓度等工艺条件对两种催化剂活性的影响趋势是一致的. 相似文献
9.
血液中有关生化指标的变化,可准确反映出运动员体内代谢情况。实验证明:淫羊藿可不同程度提高运动员血红蛋白、血糖、血乳酸水平、改善机体代谢,有利于维持高强度运动能力。特别是对长时间耐力项目基抗疲劳作用尤具特殊意义。 相似文献
10.
GAO Qingyu ZHANG Lu ZHANG Xing WANG Jichang 《科学通报(英文版)》2005,50(17):1839-1842
This study predicts that quasi-periodic oscillations could exist in a detailed model of glycolysis that is analyzed in an autonomous system. In addition to period-doubling, quasi-periodic and period-adding bifurcation, a new stationary branch, which lies in between the thermodynamic and flow branches, is also uncovered in the glycolytic reaction system. Results presented in this study illustrate that the Michaelis constant (K4GAP) of glyceraldehyde 3-phosphate dehydrogenase for glyceraldehyde 3-phosphate has great influences on glycolytic oscillations, in which increasing K4GAP widens the range of flow rate over which quasi-periodic oscillations exist. 相似文献