Adenosine triphosphate formation activities

Another enzyme used for the measurement of glucose is hexokinase (EC 2.7.1.1) which catalyses the phosphorylation of glucose to produce glucose-6-phosphate with adenosine triphosphate as the phosphate donor and magnesium ions as an activator. The rate of formation of glucose-6-phosphate can be linked to the reduction of NADP by the enzyme glucose-6-phosphate dehydrogenase (EC 1.1.1.49). This indicator reaction can be monitored spectrophotometrically at 340 nm or fluorimetrically ... 

Jhe synthesis of proteins, as characterized by the in vitro incorporation of amino acids into the protein component of cytoplasmic ribonu-cleoprotein, is known to require the nonparticulate portion of the cytoplasm, ATP (adenosine triphosphate) and GTP (guanosine triphosphate) (15, 23). The initial reactions involve the carboxyl activation of amino acids in the presence of amino acid-activating enzymes (aminoacyl sRNA synthetases) and ATP, to form enzyme-bound aminoacyl adenylates and the enzymatic transfer of the aminoacyl moiety from aminoacyl adenylates to soluble ribonucleic acid (sRNA) which results in the formation of specific RNA-amino acid complexes—see, for example, reviews by Hoagland (12) and Berg (1). The subsequent steps in pro-... 

Animal and bacterial enzymes that utilize or synthesize carbamyl phosphate have activity with acetyl phosphate. Acyl phosphatase hydrolyzes both substrates, and maybe involved in the specific dynamic action of proteins. Ornithine and aspartic transcarbamylases also synthesize acetylornithine and acetyl aspartate. Finally, bacterial carbamate kinase and animal carbamyl phosphate synthetase utilize acetyl phosphate as well as carbamyl phosphate in the synthesis of adenosine triphosphate. The synthesis of acetyl phosphate and of formyl phosphate by carbamyl phosphate synthetases is described. The mechanism of carbon dioxide activation by animal carbamyl phosphate synthetase is reviewed on the basis of the findings concerning acetate and formate activation. 

B vitamin activation, muscle relaxation, and adenosin triphosphate (ATP) formation - the energy the body runs on. Concentrations of Ca and Mg in human milk range between 250-300 and 25-35 mgl-1, respectively, but they remain constant along the entire lactating period [11],... 

CPSI catalyzes the formation of carbamoyl phosphate from bicarbonate, ammonium, and two adenosine triphosphate molecules (Fig. 18-1).This first step of the urea cycle occurs in the mitochondrial matrix and assimilates the first of the two nitrogen atoms that will eventually be found in urea. While two ATP molecules are hydrolyzed, there is formation of a lower energy bond in carbamoyl phosphate. CPSI is a homodimer that accounts for 15-30% of the total protein mass in liver mitochondria. jV-Acetylglutamate (NAG) is an essential allosteric activator of CPSI activity, and magnesium ions are also required for its activity. 

Eugene Kennedy and Albert Lehninger showed in 1949 that fatty acids are oxidized in mitochondria. Subsequent work demonstrated that they are activated before they enter the mitochondrial matrix. Adenosine triphosphate (ATP) drives the formation of a thioester linkage between the carboxyl group of a fatty acid and the sulfhydryl group of CoA. This activation reaction takes place on the outer mitochondrial membrane, where it is catalyzed by acyl CoA synthetase (also called fatty acid thiokinase). 

Fig. 31.14. Scheme describing platelet activation as it relates to blood clot formation. The thrombus is formed at the site of a damaged wall in the vasculature. Normal endothelial cells in vascular wall provide prostacyclin, which stimulates the conversion of adenosine triphosphate (ATP) to cyclic adenosine monophosphate (cAMP), preventing platelet... 

Although interferons are mediators of immune response, different mechanisms for the antiviral action of interferon have been proposed. Interferon-a possesses broad-spectrum antiviral activity and acts on virus-infected cells by binding to specific cell surface receptors. It inhibits the transcription and translation of mRNA into viral nuoleic acid and protein. Studies in cell-free systems have shown that the addition of adenosine triphosphate and double-stranded RNA to extracts of interferon-treated cells activates cellular RNA proteins and a oellular endonuclease. This activation causes the formation of translation inhibitory protein, which terminates production of viral enzyme, nucleic acid, and structural proteins (28). Interferon also may act by blocking synthesis of a cleaving enzyme required for viral release. 

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