Final answer:
ATP hydrolysis releases energy that is used to attach a phosphate group to a protein in a process called protein phosphorylation. This results in conformational changes that can alter the protein's shape and function, enabling it to perform work such as muscle contraction or active transport.
Step-by-step explanation:
The hydrolysis of ATP (adenosine triphosphate) plays a critical role in altering a protein's structure and function. When ATP is hydrolyzed, the terminal phosphate group is removed, releasing energy. This energy is then used to modify proteins in a process called protein phosphorylation, commonly through the attachment of the released phosphate group to the protein itself. The addition of a phosphate group can cause conformational changes in the protein, altering its shape and function.
For example, in muscle contraction, the hydrolysis of ATP at the binding site on myosin causes a release of actin, resulting in a change in the angle of the myosin head into a "cocked" position. This stores potential energy within the myosin head. When the conditions are right, this energy can be harnessed to perform mechanical work, such as the sliding of actin and myosin filaments during contraction. This illustrates how the energy from ATP hydrolysis is used for the mechanical work within cells.
In other cases, such as the sodium-potassium pump, ATP hydrolysis results in a change in the pump's affinity for sodium and potassium ions. This enables the pump to transport ions against their electrochemical gradients, demonstrating how ATP hydrolysis can facilitate active transport.