A peroxidase enzyme contains 2% selenium(Se=80). The minimum molecular weight of the enzyme is

Options

A. 1000
B. 2000
C. 4000
D. 800

Answer

To find the minimum molecular weight of the peroxidase enzyme that contains 2% selenium, we can follow these steps:

### Step 1: Understand the given information
We know that:
- The percentage of selenium in the enzyme is 2%.
- The atomic mass of selenium (Se) is 80 g/mol.

### Step 2: Set up the equation
Let the minimum molecular weight of the enzyme be \( M \) g/mol. According to the definition of percentage composition, we can express the percentage of selenium in the enzyme as follows:

\[ \text{Percentage of Selenium} = \left( \frac{\text{mass of Selenium}}{\text{molecular weight of enzyme}} \right) \times 100 \]

Since the enzyme contains at least one selenium atom, the mass of selenium in the enzyme is equal to its atomic mass, which is 80 g/mol. Therefore, we can write:

\[ 2 = \left( \frac{80}{M} \right) \times 100 \]

### Step 3: Rearrange the equation to solve for \( M \)
Now we can rearrange the equation to isolate \( M \):

\[ 2 = \frac{80 \times 100}{M} \]

Multiplying both sides by \( M \):

\[ 2M = 8000 \]

Now, divide both sides by 2:

\[ M = \frac{8000}{2} = 4000 \]

### Step 4: Conclusion
Thus, the minimum molecular weight of the enzyme is:

\[ \boxed{4000 \, \text{g/mol}} \]

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