One indication of the relative importance of various ATP-producing pathways is the Vmax of certain enzymes of these pathways. The values of Vmax Oof several enzymes from the pectoral muscles (chest muscles used for flying) of pigeon and pheasant are listed below. Vmax (µmol substrate/min/g tissue) Pigeon Enzyme Pheasant Hexokinase 3.0 2.3 Glycogen phosphorylase Phosphofructokinase-1 Citrate synthase Triacylglycerol lipase Discuss the relative importance of glycogen metabolism and fat metabolism in generating ATP in the pectoral muscles of these birds. b. Compare oxygen consumption in the two birds. c. Judging from the data in the table, which bird is the long-distance flyer? Justify your answer. d. Why were these enzymes selected for comparison? Would the activities of triose phosphate isomerase and malate dehydrogenase be equally good bases for comparison? Explain. 18.0 120.0 24.0 100.0 143.0 15.0 0.07 0.01 а.

The KM values for the reaction of chymotrypsin with two different substrates are given in the table below. Considering this information, which substrate has the lower apparent affinity for the enzyme? Which substrate is likely to give a lower value for Vmax? Substrate N-acetylvaline ethyl ester N-acetyltyrosine ethyl ester KM (M) 8.8 X 10-² 6.6 X 10-4 N-acetylvaline ethyl ester has the lower apparent affinity for the enzyme; it will also likely to give a lower Vmax: N-acetyltyrosine ethyl ester has the lower apparent affinity for the enzyme; it will also likely to give the lower V₁ max. N-acetylvaline ethyl ester has the lower apparent affinity for the enzyme; N- acetyltyrosine ethyl ester is likely to give the lower Vmax: N-acetyltyrosine ethyl ester has the lower apparent affinity for the enzyme; N- acetylvaline will likely to give the lower Vmax. None of the above statements are correct.

In glycolysis, fructose 1,6-bisphosphate is converted to two products with a standard free- energy change (AG) of 23.8 kJ/mol. Under what cellular conditions will the free-energy change be negative, enabling the reaction to proceed spontaneously to form products? O In a cell where the concentrations of products and reactants yield a low value of the mass-action ratio Q ○ The reaction will not go to the right spontaneously under any conditions because the AG is positive ○ The reaction will proceed spontaneously to the right if there is a high concentration of products relative to the concentration of fructose 1,6-bisphosphate ○ The reaction will proceed spontaneously to the right if there is a high concentration of enzyme to catalyze the reaction O None of these conditions is sufficient

Please provide an explanation for how to work through this practice problem:   Using table 12.1, calculate the free energy change for the synthesis of ATP from cAMP and inorganic phosphate. (Note: cAMP is hydolyzed to AMP, and the free engery of hydrolysis for ATP and ADP is approximately equal.)   Table 12.1: (Compound: Change in Free Energy in kJ/mol)   cAMP: -50.4 Creatine phosphate: -43.3 ATP: -30.5 Glucose 6-phosphate: -13.9 AMP: -9.2