Enzymes involved in biochemical reactions act as what in chemical processes?

• A. Inhibitors
• B. Catalysts
• C. Substrates
• D. Solvents

Answer: (B)

Enzymes act as catalysts in biochemical reactions, speeding up the process by lowering the activation energy needed to reach the transition state. They do this with a specific active site that binds substrates and helps align their atoms for bond-breaking and bond-forming events. After the reaction occurs, the enzyme is free to catalyze more reactions and is not consumed or permanently altered.

For example, digestive enzymes like amylase, protease, and lactase each target particular substrates, enabling reactions to proceed rapidly at body temperature. Inhibitors would slow or block enzyme activity, substrates are the molecules the enzyme acts on, and solvents are the medium in which reactions occur; enzymes themselves are not solvents.