Biochemical reactions are regulated by catalysts called ...........

Explanation

**Step-by-Step Solution:**

1. **Understanding Biochemical Reactions**: Biochemical reactions refer to the chemical processes that occur within living organisms, where molecules are transformed into different molecules. These reactions are essential for various cellular functions.

2. **Role of Catalysts**: Catalysts are substances that speed up chemical reactions without being consumed in the process. They lower the activation energy required for the reaction to occur, making it easier for the reaction to proceed.

3. **Biological Catalysts**: In the context of living organisms, the catalysts that regulate biochemical reactions are known as biological catalysts. These are specifically tailored to function within the unique conditions present in biological systems.

...