Energy cellular

This type of correlation applies to almost any siibstrate involved in cellular energy metabolism and is supported by experimental data and energetic considerations. However, it is based on assumptions true at or near the steady-state equilibrium conditions and may not be valid... 

Cell membrane The cell membrane is composed of about 45% lipid and 55% protein. The lipids form a bilayer that is a continuous nonpolar hydrophobic phase in which the proteins are embedded. The cell membrane is a highly selective permeability barrier that controls the entry of most substances into the cell. Important enzymes in the generation of cellular energy are located in the membrane. 

Nearly all biological processes involve the specialized functions of one or more protein molecules. Proteins function to produce other proteins, control all aspects of cellular metabolism, regulate the movement of various molecular and ionic species across membranes, convert and store cellular energy, and carry out many other activities. Essentially all of the information required to initiate, conduct, and regulate each of these functions must be contained in... 

Clearly, the activity of phosphofructokinase depends both on ATP and AMP levels and is a function of the cellular energy status. Phosphofructokinase activity is increased when the energy status falls and is decreased when the energy status is high. The rate of glycolysis activity thus decreases when ATP is plentiful and increases when more ATP is needed. 

Atkinson, D. E., 1977. Cellular Energy Metabolism and Its Regulation. New York Academic Press. 

Rolfe, D. F., and Brown, G. C., 1997. Cellular energy utilization and molecular oriffin of standard metabolic rate in mammals. Physiological Reviews 77 731-758. 

Otherwise it has been shown that the accumulation of electrolytes by many cells runs at the expense of cellular energy and is in no sense an equilibrium condition 113) and that the use of equilibrium thermodynamic equations (e.g., the Nemst-equation) is not allowed in systems with appreciable leaks which indicate a kinetic steady-state 114). In addition, a superposition of partial current-voltage curves was used to explain the excitability of biological membranes112 . In interdisciplinary research the adaptation of a successful theory developed in a neighboring discipline may be beneficial, thus an attempt will be made here, to use the mixed potential model for ion-selective membranes also in the context of biomembrane surfaces. 

Atkinson, D.E. (1977). In Cellular Energy Metabolism and its Regulation. Academic Press, New York. Babcock, G.T. Wikstrom, M. (1992). Oxygen activation and the conservation of energy in cell respiration. Nature 356, 301-309. 

Wallimann, T., Wyss. M., Brdicza, D., Nicolay, K.. Eppenberger, H.M. (1992). Intracellular compartmentation. structure and function of creatine kinase isoenzymes in tissues with high and fluctuating energy demands The phosphocreatine circuit for cellular energy homeostasis. Biochem. J. 281,21-40. 

The phosphate group is derived from phosphoric acid (H3 PO4) by replacing an O—H bond by an O—C or O— P bond. Phosphate is an important functional group in biochemistry, being involved in cellular energy production as well as acting as an important monomer in biopolymers, particularly in DNA. Bonds to phosphate groups form or break in the course of a number of important biochemical reactions. 

At least two enzymes compete for acetyl-CoA - the citrate synthase and 3-ke-tothiolase. The affinities of these enzymes differ for acetyl-CoA (Table l),and at low concentrations of it the citrate synthase reaction tends to dominate, provided that the concentration of 2/H/ is not inhibiting. The fine regulation of the citrate synthases of various poly(3HB) accumulating bacteria has been studied [ 14, 47, 48]. They appear to be controlled by cellular energy status indicators (ATP, NADH, NADPH) and/or intermediates of the TCA cycle. The 3-ketothio-lase has also been investigated [10-14,49, 50]. This enzyme is, above all, inhibited by CoASH [10,14,49]. This important feature will be further considered below. 

After binding to a proteinaceous membrane carrier, drugs are carried across the membrane (with the expenditure of cellular energy), where they are released... 

Interstitial nucleotides are derived from intracellular sources. In addition to its central role in cellular energy metabolism, ATP is a classical neurotransmitter that is packaged into secretory granules of neurons and adrenal chromafin cells and released in quanta in response to... 

Pharmacological approaches to finding antidotes for cyanide are also under investigation. Maduh et al. (1995) examined the effects of a protein kinase C inhibitor, l-5-(isoquinolinesulfonyl)-2 methylpiperazine (H-7), on cellular energy depletion caused by sodium cyanide. They reported that H-7 partially prevented cellular energy depletion and increased the number of surviving cells. 

Table 7.11 Some Cellular Energy Transfer Reactions. ...

Aerobic respiration The biological process during which animals and some bacteria oxidize organic carbon to carbon dioxide to yield cellular energy. The oxidizing agent is O2. 

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