- The class of biomolecules that primarily functions as biological catalysts to accelerate metabolic reactions is proteins.

- Enzymes, which are specialized proteins, play a crucial role in lowering the activation energy required for biochemical reactions, thereby significantly increasing the reaction rate.
- Unlike other biomolecules, proteins have complex three-dimensional structures that allow them to interact specifically with their substrates.
- This specificity is essential for regulating various metabolic pathways within the cell.

- Carbohydrates mainly serve as energy sources and structural components, while lipids are primarily involved in energy storage and forming biological membranes.
- Nucleic acids, such as DNA and RNA, are responsible for storing and transmitting genetic information rather than catalyzing reactions.

In summary, proteins act as enzymes, which are biological catalysts essential for maintaining the efficiency and regulation of metabolic processes in living organisms.