In: Chemistry
if an ATP molecule is hydrolyzed (by two water molecules) all the way to AMP (and two Pi) in two steps, how many total kcal/mol of energy could be released? Explain.
Using this equation.
ADP + H2O -> AMP + Pi + 7.3 kcal/mo
Removing or adding one phosphate group interconverts ATP to ADP or ADP to AMP. Breaking one phosphoanhydride bond releases 7.3 kcal/mol of energy.
ATP+H2O→ADP+Pi(ΔG = -30.5 kJ/mol)(ΔG = -30.5 kJ/mol)ATP+H2O→ADP+Pi
ATP+H2O→AMP+2Pi(ΔG = -61 kJ/mol)(ΔG = -61 kJ/mol)ATP+H2O→AMP+2Pi
2ADP+H2O→2AMP+2Pi(ΔG = -61 kJ/mol)(ΔG = -61 kJ/mol)2ADP+H2O→2AMP+2Pi
At pH 7,
ATP+4−H2O⇌ADP3−+HPO2−4+H+ATP+4−H2O⇌ADP3−+HPO42−+H+
The ATP hydrolysis an exergonic reaction
ATP in the Cell
ATP is the primary energy transporter for most energy-requiring reactions that occur in the cell. The continual synthesis of ATP and the immediate usage of it results in ATP having a very fast turnover rate. This means that ADP is synthesized into ATP very quickly and vice versa. For example, it takes only a few seconds for half of the ATP molecules in a cell to be converted into ADP to be used in driving endergonic (non-spontaneous) reactions and then converted back into ATP using exergonic (spontaneous..