Complex-I in electron transpo chain is ?
**Core Concept**
The electron transport chain is a series of protein complexes located in the mitochondrial inner membrane, playing a crucial role in cellular respiration. **Complex I**, also known as NADH:ubiquinone oxidoreductase, is the first and largest enzyme in the transport chain. It initiates the process by transferring electrons from **NADH** to **ubiquinone**.
**Why the Correct Answer is Right**
**Complex I** is indeed **NADH:ubiquinone oxidoreductase**, facilitating the transfer of electrons from **NADH** to **ubiquinone**, thereby contributing to the generation of the proton gradient across the mitochondrial membrane. This process is essential for the production of **ATP** through **oxidative phosphorylation**.
**Why Each Wrong Option is Incorrect**
**Option A:** Incorrect because it does not specify the role or components of Complex I.
**Option B:** Incorrect as it does not accurately describe the function or location of Complex I.
**Option C:** Incorrect because, although related to the electron transport chain, it does not accurately represent Complex I.
**Clinical Pearl / High-Yield Fact**
Remember, defects in **Complex I** can lead to neurodegenerative diseases and are associated with **mitochondrial myopathies**. Understanding the electron transport chain is crucial for diagnosing and managing these conditions.
**Correct Answer:** D. NADH:ubiquinone oxidoreductase