Little quantity influences the rate of chemical reaction

Options

A. Hormone
B. Enzyme
C. Catalyst
D. Alkaloids.

Answer

To solve the question regarding which little quantity influences the rate of a chemical reaction, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Question**: The question asks which of the given options, in small quantities, can influence the rate of a chemical reaction.

2. **Analyze Each Option**:
- **Hormone**: Hormones are signaling molecules that can regulate various biological processes but do not directly influence the rate of chemical reactions.
- **Enzyme**: Enzymes are biological catalysts that accelerate chemical reactions. They can significantly lower the activation energy required for reactions to occur, thus influencing the rate of reaction even in small quantities.
- **Catalyst**: While catalysts (including enzymes) do influence the rate of reactions, the term is broader and does not specify a biological context. However, catalysts can also function in small amounts.
- **Alkaloids**: Alkaloids are a class of compounds that can have various effects in biological systems but do not primarily serve as catalysts to influence reaction rates.

3. **Identify the Correct Answer**: Among the options provided, the enzyme is the most relevant choice as it is a specific type of catalyst that can influence the rate of chemical reactions in small amounts.

4. **Conclusion**: The correct answer is **enzyme**, as it is known to accelerate biochemical reactions and can do so in little quantities.

### Final Answer:
The little quantity that influences the rate of chemical reaction is **enzyme**.

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