5. Given the following information tables, determine in which cell type cleavage of the terminal phosphate from ADP yields the greatest actual change in free energy. (Please work in kJ/mol.) TABLE 13-6 Standard Free Energies of Hydrolysis of Some Phosphorylated Compounds and Acetyl-CoA (a Thioester) TABLE 13-5 Total Concentrations of Adenine Nucleotides, Inorganic Phosphate, and Phosphocreatine in Some Cells AG (kJimol) (kcalimol) Concentration (MM) Phosphoenolpyruvate 1,3-Bisphosphoglycerate (+3-phosphoglycerate + P) Phosphocreatine -61.9 -14.8 ATP ADP AMP P, PCr Rat hepatocyte Rat myocyte 49.3 -11.8 3.38 1.32 0.29 4.8 -43.0 -103 8.05 0.93 0.04 8.05 28 ADP (+ AMP + P) -32.8 -7.8 -7.3 Rat neuron 2.59 0.73 0.06 2.72 4.7 ATP (+ ADP + P) Location of -30.5 Human erythrocyte 225 0.25 0.02 1.65 ATP (+ AMP • PP) AMP (+ adenosine P) cleavage is important! 45.6 -10.9 E. coli cell 7.90 1.04 0.82 7.9 -14.2 -34 For erythrocytes the concentrations are those of the cytosol (human erythrocytes lack a nucleus and mitochondria). In the other types of cells the data are for the entire cell contents, although the cytosol and the mitochondria have very different concentrations of ADP. PCr is phosphocreatine, discussed on p. 516. R This value reflects total concentration; the true value for free ADP may be much lower (p. 509). PP, (+ 2P) -19.2 -4.0 Sources: Data mostly from W. P. Jencks, in Handbook of Biochemistry and Molecular Biology, 3rd edn (G. D. Fasman, ed.), Physical and Chemical Data, Vol. 1, p. 296. CRC Press, 1976. Value for the free energy of hydrolysis of PP, from P.A. Frey and A Arabshahi, Biochemistry 34:11,307, 1995. A. Write out (in words) this reaction, in the proper direction. B. What is the standard free energy change of this reaction? Include units. C. Calculate the actual free energy change for this reaction in rat hepatocytes. Show all work. Include units. D. Calculate the actual free energy change for this reaction in rat myocytes. Show all work. Include units. E. Calculate the actual free energy change for this reaction in rat neurons. Show all work. Include units. F. Can you identify any trends between the actual free energy released and the concentrations of ADP, AMP, or inorganic phosphate in the cells? If so, what might those trends be?

5. Given the following information tables, determine in which cell type cleavage of the terminal phosphate from ADP yields the greatest actual change in free energy. (Please work in kJ/mol.) TABLE 13-6 Standard Free Energies of Hydrolysis of Some Phosphorylated Compounds and Acetyl-CoA (a Thioester) TABLE 13-5 Total Concentrations of Adenine Nucleotides, Inorganic Phosphate, and Phosphocreatine in Some Cells AG (kJimol) (kcalimol) Concentration (MM) Phosphoenolpyruvate 1,3-Bisphosphoglycerate (+3-phosphoglycerate + P) Phosphocreatine -61.9 -14.8 ATP ADP AMP P, PCr Rat hepatocyte Rat myocyte 49.3 -11.8 3.38 1.32 0.29 4.8 -43.0 -103 8.05 0.93 0.04 8.05 28 ADP (+ AMP + P) -32.8 -7.8 -7.3 Rat neuron 2.59 0.73 0.06 2.72 4.7 ATP (+ ADP + P) Location of -30.5 Human erythrocyte 225 0.25 0.02 1.65 ATP (+ AMP • PP) AMP (+ adenosine P) cleavage is important! 45.6 -10.9 E. coli cell 7.90 1.04 0.82 7.9 -14.2 -34 For erythrocytes the concentrations are those of the cytosol (human erythrocytes lack a nucleus and mitochondria). In the other types of cells the data are for the entire cell contents, although the cytosol and the mitochondria have very different concentrations of ADP. PCr is phosphocreatine, discussed on p. 516. R This value reflects total concentration; the true value for free ADP may be much lower (p. 509). PP, (+ 2P) -19.2 -4.0 Sources: Data mostly from W. P. Jencks, in Handbook of Biochemistry and Molecular Biology, 3rd edn (G. D. Fasman, ed.), Physical and Chemical Data, Vol. 1, p. 296. CRC Press, 1976. Value for the free energy of hydrolysis of PP, from P.A. Frey and A Arabshahi, Biochemistry 34:11,307, 1995. A. Write out (in words) this reaction, in the proper direction. B. What is the standard free energy change of this reaction? Include units. C. Calculate the actual free energy change for this reaction in rat hepatocytes. Show all work. Include units. D. Calculate the actual free energy change for this reaction in rat myocytes. Show all work. Include units. E. Calculate the actual free energy change for this reaction in rat neurons. Show all work. Include units. F. Can you identify any trends between the actual free energy released and the concentrations of ADP, AMP, or inorganic phosphate in the cells? If so, what might those trends be?

Biology: The Dynamic Science (MindTap Course List)

4th Edition

ISBN:9781305389892

Author:Peter J. Russell, Paul E. Hertz, Beverly McMillan

Publisher:Peter J. Russell, Paul E. Hertz, Beverly McMillan

Chapter4: Cells

Section: Chapter Questions

Problem 1ITD

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