Which has both Fe and Cu as prosthetic group?

Options

A. Haemoglobin
B. Dehydrogenase
C. Polymerase
D. Cytochrome oxidase

Answer

To determine which option has both iron (Fe) and copper (Cu) as prosthetic groups, let's analyze each option step by step:

### Step 1: Understand the term "prosthetic group"
A prosthetic group is a non-polypeptide unit that is tightly and permanently attached to a protein and is essential for the biological activity of that protein. It can be an organic molecule (like a vitamin) or an inorganic metal ion.

**Hint:** Remember that prosthetic groups are not made of amino acids and are crucial for the function of the protein.

### Step 2: Analyze each option
1. **Hemoglobin**:
- Hemoglobin contains iron (Fe) as a prosthetic group (in the form of heme) but does not contain copper (Cu).

**Hint:** Hemoglobin is primarily known for its role in oxygen transport and contains iron.

2. **Dehydrogenase**:
- Some dehydrogenases may contain copper (Cu) as a prosthetic group, but they do not typically contain iron (Fe).

**Hint:** Dehydrogenases are involved in oxidation-reduction reactions and may have various metal ions, but not both Fe and Cu together.

3. **Polymerase**:
- Polymerases do not have a prosthetic group; they are enzymes that synthesize nucleic acids (DNA or RNA) and do not require metal ions as prosthetic groups.

**Hint:** Polymerases are primarily involved in the synthesis of nucleic acids and do not utilize metal ions as prosthetic groups.

4. **Cytochrome oxidase**:
- Cytochrome oxidase contains both iron (Fe) and copper (Cu) as prosthetic groups. It is an enzyme that plays a critical role in the electron transport chain.

**Hint:** Cytochrome oxidase is essential for cellular respiration and is located in the mitochondrial membrane.

### Step 3: Conclusion
After analyzing all the options, the correct answer is **cytochrome oxidase**, as it is the only option that contains both iron and copper as prosthetic groups.

**Final Answer:** The correct option is **cytochrome oxidase**.