Which is not a protein in ETC?

Options

A. Ubiquinone
B. Cytochrome
C. Cytochrome oxidase
D. None of these

Answer

To solve the question "Which is not a protein in ETC?", we will follow these steps:

### Step 1: Understand the Electron Transport Chain (ETC)
The Electron Transport Chain (ETC) is a series of complexes and proteins located in the inner mitochondrial membrane. It plays a crucial role in cellular respiration by transferring electrons from electron donors to electron acceptors via redox reactions.

**Hint:** Remember that the ETC is primarily composed of proteins and coenzymes that facilitate electron transfer.

### Step 2: Identify the Components of the ETC
The ETC consists of various components including:
- **Proteins**: These include cytochromes and other associated enzymes.
- **Coenzymes**: These are non-protein molecules that assist in the electron transfer process.

**Hint:** Focus on distinguishing between proteins and non-protein components in the ETC.

### Step 3: Analyze the Options
The question provides several options, among which we need to identify which one is not a protein:
1. **Ubiquinone** (also known as Coenzyme Q)
2. **Cytochrome**
3. **Cytochrome oxidase**

**Hint:** Recall the definitions of each option to determine their nature (protein vs. non-protein).

### Step 4: Determine Which is Not a Protein
- **Ubiquinone**: This is a coenzyme, not a protein. It plays a role in the transport of electrons between different protein complexes in the ETC.
- **Cytochrome**: This is a protein that contains heme and is involved in electron transfer.
- **Cytochrome oxidase**: This is a protein complex that acts as the terminal enzyme in the ETC.

**Hint:** Identify which option does not fit the category of proteins based on their definitions.

### Step 5: Conclusion
Based on the analysis, the correct answer to the question "Which is not a protein in ETC?" is **Ubiquinone**.

**Final Answer:** Ubiquinone is not a protein in the Electron Transport Chain.

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