Energy muscular

Phosphorus Component of DNA, cellular energy Muscular weakness, bone pain, appetite loss Meat, poultry, fish, eggs, beans, milk 800... 

The human body has more than 600 muscles. The body s movement is performed by muscle contractions, which are stimulated by the nervous system. This system links muscle tissue to the spinal cord and brain. The network of nerve cells which carries the brain s signals directs the flow of muscular energy. Most muscular activity occurs beyond the range of the conscious mind. The body, working through the neuromuscular network, manages... 

From the perspective of general energetics, the long span of human prehistoric development can be seen as the quest for a more efficient use of somatic energy, the muscular exertions used primarily to secure a basic food supply and then to gradually improve shelters, acquire more material possessions, and evolve a variety of cultural expressions. This quest was always limited by fundamental bioenergetic considerations Fifty to ninety watts is the limit of nsefnl work that healthy adults can snstain for prolonged periods of time (of course, short bursts of effort could reach hundreds of watts). 

The process by which yeast breaks down glucose has been carefully studied by biochemists and the way in which this transformation occurs is now known in considerable detail. One of the reasons this process is so interesting is that a nearly identical process takes place in human muscle, in this case to furnish energy needed for muscular activity. 

The vital processes—eg, synthetic reactions, muscular contraction, nerve impulse conduction, and active transport—obtain energy by chemical linkage, or coupling, to oxidative reactions. In its simplest form, this type of coupling may be represented as shown in Figure 10—1. The conversion of metabolite A to metabolite B... 

Figure 12-14. The creatine phosphate shuttle of heart and skeletal muscle. The shuttle allows rapid transport of high-energy phosphate from the mitochondrial matrix into the cytosol. CKg, creatine kinase concerned with large requirements for ATP, eg, muscular contraction CIC, creatine kinase for maintaining equilibrium between creatine and creatine phosphate and ATP/ADP CKg, creatine kinase coupling glycolysis to creatine phosphate synthesis CK, , mitochondrial creatine kinase mediating creatine phosphate production from ATP formed in oxidative phosphorylation P, pore protein in outer mitochondrial membrane.

Griffiths, RD., Cady, E.B., Edwards, RH.T. and Wilkie, D.R (1985). Muscle energy metabolism in Duchenne muscular... 

The carbohydrate metabolic routes in various tissues of the organism discussed above differ in intensity, which is defined by metabolic features specific of each tissue and organ. However, from the standpoint of activity of the whole organism, certain specializations of the carbohydrate metabolic routes in individual tissues are profitably complementary. For example, strenuous muscular exertion requires energy which is initially supplied by the breakdown of glycogen to lactic acid. The latter compound is excreted into the blood to be supplied... 

Diseases of muscle are usually classified as muscular dystrophies, inflammatory or congenital myopathies, metabolic disorders affecting the muscle, and neurological diseases affecting the innervation of the muscle (so-called motor neuron diseases). In the past, the energy metabolism of some muscular diseases... 

Pain, muscular weakness, cramps and ease of fatigue are the most usual symptoms of muscular disease. In most cases, it is diseases of the vascular or nervous system or problems with the processes providing energy within the muscle that are responsible for clinical problems with muscles. Other clinical problems include the muscular dystrophies, myotonic disorders, inflammatory myopathies and disorders of neuromuscular transmission (see Walton, 1996). The best known is Duchenne muscular dystrophy. 

Severe thiamine vitamin Bf) deficiency results in beriberi. The symptoms can include growth retardation, muscular weakness, apathy, edema, and heart failure. Neurological symptoms, such as personality changes and mental deterioration, also may be present in severe cases. Because of the role played by thiamine in metabolic processes in all cells, a mild deficiency may occur when energy needs are increased. Since thiamine is widely distributed in food, beriberi is rare except in communities existing on a single staple cereal food. The disease does occur with some frequency in alcoholics, whose poor diet may lead to an inadequate daily intake of thiamine. 

CFS patients and is related to autonomic dysfunction. In a separate rat study, Giannesini et al. used citrulline malate (CM) to treat asthenia and found that the supplementation prevented the basal PCr/ATP ratio reduction and normalized the pHi time-course during muscular activ-ity. They conclude that CM supplementation corrects the impaired control of oxidative function and has protective effect on basal energy metabolism. The data from either human or animal studies provide a potential approach to therapy. 

As an attempt to connect the first discussion, which was concerned with diffusion-reaction coupling, with Dr. Williams presentation of enzymes as dynamic systems, I wanted to direct attention to a number of specific systems. These are the energy-transducing proteins that couple scalar chemical reactions to vectorial flow processes. For example, I am thinking of active transport (Na-K ATPase), muscular contraction (actomyosin ATPase), and the light-driven proton pump of the well-known purple... 

ATP is a crucial intermediate for cells to maintain normal activities without a minimum level, the cell will die as systems will fail. ATP is the energy currency of the cell and is required for the synthesis of many substances such as macromolecules for structural and functional purposes, which the cell needs, but also for processes such as cell division, maintenance of the correct ionic balance, muscular and electrical activity, ciliary movement, membrane transporters, and specific ion channels. 

Other large animals, such as the elephant and rhinoceros, have similar metabolic characteristics, as do diving mammals such as whales and seals. Dinosaurs and other huge, now-extinct animals probably had to depend on lactic acid fermentation to supply energy for muscular activity, followed by very long recovery periods during which they were vulnerable to attack by smaller predators better able to use oxygen and thus better adapted to continuous, sustained muscular activity. 

Creatine phosphate (also called phosphocreatine), the phosphory-lated derivative of creatine found in muscle, is a high-energy compound that can reversibly donate a phosphate group to ADP to form ATP (Figure 21.16). Creatine phosphate provides a small but rapidly mobilized reserve of high-energy phosphates that can be used to maintain the intracellular level of ATP during the first few minutes of intense muscular contraction. [Note The amount of creatine phosphate in the body is proportional to the muscle mass.]... 

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