How many enzymes are required for the breakdown of Lactose in E.coll?

Options

A. one
B. two
C. three
D. four

Explanation

To determine how many enzymes are required for the breakdown of lactose in E. coli, we can follow these steps:

### Step 1: Understand the breakdown of lactose
Lactose is a disaccharide sugar composed of glucose and galactose. To utilize lactose, E. coli needs to break it down into its monosaccharide components.

### Step 2: Identify the enzymes involved
In E. coli, the breakdown of lactose involves three specific enzymes, which are encoded by genes in the lac operon:

1. **Beta-galactosidase (encoded by gene Z)**: This enzyme hydrolyzes lactose into glucose and galactose.
2. **Permease (encoded by gene Y)**: This enzyme facilitates the transport of lactose into the bacterial cell.
3. **Transacetylase (encoded by gene A)**: While its exact role in lactose metabolism is less clear, it is involved in the metabolism of lactose and is part of the lac operon.

### Step 3: Conclusion
Thus, the total number of enzymes required for the breakdown of lactose in E. coli is three.

### Final Answer
The answer is **3 enzymes**.

---