After being heated, an enzyme loses its ability to catalyze a reaction. What change occurred to the enzyme?
A. A physical change, because cooling will restore the enzyme's function
C. A physical change, because intermolecular forces were overcome
C is the answer
D. The enzyme lost its sense of humor and couldn't find anything funny to catalyze
The correct answer is C. A physical change, because intermolecular forces were overcome.
Heating an enzyme can cause its protein structure to denature, which means the intermolecular forces that hold the enzyme's structure together are disrupted. This disrupts the enzyme's active site and prevents it from binding to its substrate, thereby losing its ability to catalyze a reaction. Cooling the enzyme may help to restore its structure and functionality.
The correct answer is C. A physical change, because intermolecular forces were overcome.
Enzymes are proteins that act as catalysts, meaning they speed up chemical reactions. They have a specific structure, including a three-dimensional shape, that is crucial for their function. When an enzyme is heated, the increase in temperature disrupts the weak intermolecular forces, such as hydrogen bonds and van der Waals forces, that hold the enzyme's structure together. This disruption causes the enzyme to undergo denaturation.
Denaturation is a process in which the enzyme loses its original shape, leading to a loss of its catalytic activity. This change is considered a physical change because it does not involve any chemical reactions or alterations in the enzyme's molecular composition. Instead, it is caused by the breaking of non-covalent bonds responsible for maintaining the enzymatic structure.
It is important to note that once an enzyme is denatured, simply cooling it down will not necessarily restore its function. The process of denaturation is often irreversible, and the enzyme may require specific conditions or assistance (such as chaperone proteins) to refold correctly.