Molecules with limited metabolic activity are called

Options

A. Protocells
B. Protists
C. Protobionts
D. Protostomes

Answer

To answer the question "Molecules with limited metabolic activity are called," we need to identify the correct term that describes such molecules.

### Step-by-Step Solution:

1. **Understanding Metabolic Activity**:
- Metabolic activity refers to the biochemical processes that occur within a living organism to maintain life. Molecules involved in these processes are typically active and play a role in metabolism.

2. **Identifying the Type of Molecules**:
- Molecules with limited metabolic activity are generally those that do not actively participate in metabolic processes or are not involved in the primary functions of metabolism.

3. **Common Terms in Biology**:
- In biology, there are specific terms used to describe molecules based on their activity. For instance, "metabolites" are substances involved in metabolism, while "proenzymes" or "inactive forms" refer to molecules that may not have metabolic activity until activated.

4. **Finding the Correct Term**:
- The term that is commonly used to describe molecules with limited or no metabolic activity is "metabolically inactive" or "inactive molecules." However, in a more specific context, such molecules can also be referred to as "zymogens" if they are inactive precursors of enzymes.

5. **Conclusion**:
- Based on the understanding of metabolic activity and the terminology used in biology, the answer to the question is that molecules with limited metabolic activity are called "inactive molecules" or "zymogens."

### Final Answer:
Molecules with limited metabolic activity are called **inactive molecules** or **zymogens**.