Which of the following products are obtained by anaerobic respiration from yeast ?

Options

A. Beer and wine
B. Alcohols
C. `CO_(2)`
D. All of these

Answer

To solve the question "Which of the following products are obtained by anaerobic respiration from yeast?", we can follow these steps:

### Step-by-Step Solution:

1. **Understand Anaerobic Respiration in Yeast**:
- Anaerobic respiration occurs in the absence of oxygen. In yeast, this process begins with glucose as the initial substrate.

2. **Glycolysis**:
- The first step in anaerobic respiration is glycolysis, where glucose is broken down into two molecules of pyruvic acid. This step is common to both aerobic and anaerobic respiration.

3. **Decarboxylation**:
- The pyruvic acid then undergoes decarboxylation, which is the removal of carbon dioxide (CO2). This reaction is facilitated by the enzyme decarboxylase, resulting in the formation of two molecules of acetaldehyde and the release of two molecules of CO2.

4. **Formation of Ethyl Alcohol**:
- The acetaldehyde produced then undergoes a reduction process (dehydrogenesis) in the presence of the enzyme dehydrogenase, resulting in the formation of two molecules of ethyl alcohol (ethanol).

5. **Products of Anaerobic Respiration**:
- The overall products of anaerobic respiration in yeast are:
- Two molecules of carbon dioxide (CO2)
- Two molecules of ethyl alcohol (ethanol)
- Additionally, some ATP (energy) is produced.

6. **Consider the Options**:
- Now, we can analyze the options provided:
- Option A: Beer and wine - These are products of fermentation, which involves anaerobic respiration.
- Option B: Alcohols - Ethyl alcohol is produced during anaerobic respiration.
- Option C: CO2 - Carbon dioxide is also produced during the process.
- Option D: All of these - This option includes all the previous products.

7. **Conclusion**:
- Since all the products mentioned in options A, B, and C are indeed produced during anaerobic respiration in yeast, the correct answer is option D: all of these.

### Final Answer:
**The correct answer is D: all of these.**

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