What is the chemical reaction that takes place in yeast? Mention the condition.

Explanation

### Step-by-Step Text Solution:

1. **Identify the Chemical Reaction in Yeast**: The primary chemical reaction that occurs in yeast is fermentation. This process is crucial for yeast to convert sugars into energy.

2. **Conditions for the Reaction**: Fermentation in yeast occurs under anaerobic conditions, meaning it takes place in the absence of oxygen. This is a key factor for the fermentation process to occur.

3. **Substrates Involved**: The main substrate used in the fermentation process is glucose. Yeast cells convert glucose into pyruvate through glycolysis.

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