During curdling of milk, what happens to sugar present in it?

Explanation

### Step-by-Step Solution:

1. **Understanding the Composition of Milk**: Milk contains various components, including proteins, fats, and sugars. The primary sugar present in milk is lactose.

2. **Curdling of Milk**: Curdling of milk occurs when it is exposed to certain bacteria or acids. This process is often initiated by the addition of bacteria that ferment lactose.

3. **Role of Bacteria**: The bacteria present in the milk, such as Lactobacillus, produce an enzyme called lactase. This enzyme is responsible for breaking down lactose.

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