The bread dough rises because of :

Options

A. heat
B. grinding
C. growth of yeast cells
D. kneading

Answer

**Step-by-Step Solution:**

1. **Understanding the Process of Fermentation:**
- The rising of bread dough is primarily due to a process known as fermentation. This is a biological process where microorganisms convert sugars into alcohol and carbon dioxide in the absence of oxygen.

2. **Role of Yeast:**
- The specific microorganism responsible for fermentation in bread making is yeast, which is a type of unicellular fungi. Yeast thrives in anaerobic conditions, meaning it can grow and function without oxygen.

3. **Chemical Changes During Fermentation:**
- During fermentation, yeast consumes sugars present in the dough and converts them into ethanol (alcohol) and carbon dioxide (CO2). The production of CO2 is crucial as it creates gas bubbles in the dough.

4. **Effect of CO2 on Dough:**
- The carbon dioxide produced during fermentation gets trapped in the dough, causing it to expand and rise. This is what gives bread its light and airy texture.

5. **Growth of Yeast Cells:**
- As the fermentation process continues, the population of yeast cells increases. The more yeast cells present, the more CO2 is produced, leading to a greater rise in the dough.

6. **Conclusion:**
- Therefore, the bread dough rises primarily due to the growth of yeast cells and the subsequent production of carbon dioxide during fermentation.

**Final Answer:**
The bread dough rises because of the growth of yeast cells during fermentation, which produces carbon dioxide gas.

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