The sequence of reactions involved in the production of biogas is

Options

A. Hydrolysis - Methanogenesis - Hydrolysis
B. Acetogenesis - Methanogenesis - Hydrolysis
C. Hydrolysis - Hydrolysis - Acetogenesis
D. Hydrolysis - Acetogenesis - Methanogenesis

Answer

To solve the question regarding the sequence of reactions involved in the production of biogas, we can break it down into the following steps:

### Step-by-Step Solution:

1. **Understanding Biogas Production**:
- Biogas is produced through the anaerobic digestion of organic matter, which involves a series of biochemical reactions.

2. **Step 1: Hydrolysis**:
- The first step in the production of biogas is **hydrolysis**. In this process, large organic molecules (such as carbohydrates, fats, and proteins) are broken down into smaller, soluble molecules (like sugars, fatty acids, and amino acids) by the action of water and enzymes.

3. **Step 2: Acetogenesis**:
- The second step is **acetogenesis**. During this phase, the small dissolved molecules produced from hydrolysis are further converted into acetic acid (acetate) and hydrogen gas. This step is crucial as it prepares the substrates for the final step of biogas production.

4. **Step 3: Methanogenesis**:
- The final step is **methanogenesis**. In this stage, the acetic acid and hydrogen produced in the previous step are converted into methane (CH₄) and carbon dioxide (CO₂) by methanogenic microorganisms. This is the key reaction that produces the biogas.

5. **Conclusion**:
- The correct sequence of reactions involved in the production of biogas is: **Hydrolysis → Acetogenesis → Methanogenesis**.

### Final Answer:
The sequence of reactions involved in the production of biogas is **Hydrolysis, Acetogenesis, Methanogenesis**.