Here's why:
* Enzymes are biological catalysts: They speed up chemical reactions without being consumed in the process.
* Proteins are the most common type of enzyme: Their complex structures allow for precise binding of specific molecules (substrates) and the facilitation of reactions.
* There are a few exceptions: While most enzymes are proteins, some are ribozymes, which are catalytic RNA molecules. These are less common but still important in cellular processes.
So, while the statement is mostly true, it's important to remember the existence of ribozymes as exceptions.
