* Enzymes are biological catalysts: They speed up chemical reactions within living organisms without being consumed in the process.

* Proteins have complex structures: Their unique shapes and folds allow them to bind specifically to molecules called substrates. This interaction facilitates the chemical reactions they catalyze.

While the other molecules you listed play crucial roles in the body, they are not enzymes:

* Carbohydrates are primarily used for energy storage and structural support.

* Lipids (fats and oils) provide energy, insulation, and cell membrane structure.

* Nucleic acids (DNA and RNA) store and transmit genetic information.

Let me know if you'd like more information about any of these biomolecules!