Energy Changes and Metabolism

Objectives:

Key Equations:
DG=DG+ RT ln (Prod)/Reactants}

Life is a spontaneous process relying on chemical reactions (metabolism) in order to continue.  Understanding metabolism requires examining of chemical reactions and the associated energy changes that occur.  For example, consider the transfer of a phosophate group from ATP to glucose to form glucose-6-phosphate and ADP; a reaction catalyzed by hexakinase (kinases are a family of enzymes that catalyze the transfer of phosphate groups from ATP to other molecules):

                                                     Hexakinase 

Glucose    +    ATP        <------------>   Glucose-6-phosphate    +    ADP   + H+
Energy is required to break the O-P bond in ATP to free a phoshpate group; energy is then released when the phosphate group is attached to glucose.
 
 
 

Kinases are specialized transferases that regulate metabolism by transferring phosphate from ATP to other molecules