Enzyme which is a marker for mitochondria is
**Core Concept**
The question is asking about an enzyme that serves as a marker for mitochondria, highlighting the importance of mitochondrial function in cellular processes. Mitochondrial markers are enzymes that are specifically located within the mitochondria and play a crucial role in energy production, cellular respiration, and other mitochondrial functions.
**Why the Correct Answer is Right**
The correct answer is **Cytochrome C Oxidase (CCO)**, also known as Complex IV. It is a key enzyme in the electron transport chain, located in the mitochondrial inner membrane, and is responsible for the final step in oxidative phosphorylation. CCO is a crucial marker for mitochondrial function and is often used as a diagnostic tool to assess mitochondrial damage or dysfunction. The enzyme is also involved in the transfer of electrons from reduced cytochrome c to oxygen, generating a proton gradient that drives ATP synthesis.
**Why Each Wrong Option is Incorrect**
**Option A:** **Lactate Dehydrogenase (LDH)** is an enzyme found in various cellular compartments, including the cytoplasm, mitochondria, and peroxisomes. While it is involved in energy metabolism, it is not a specific marker for mitochondria.
**Option B:** **Glucose-6-phosphate dehydrogenase (G6PD)** is an enzyme located in the cytoplasm and is involved in the pentose phosphate pathway, which generates NADPH and pentoses. It is not a mitochondrial marker.
**Option C:** **Pyruvate Dehydrogenase (PDH)** is an enzyme complex that links glycolysis to the citric acid cycle, but it is located in the mitochondrial matrix. While it is involved in mitochondrial function, it is not a specific marker for mitochondria.
**Clinical Pearl / High-Yield Fact**
Mitochondrial dysfunction is associated with a range of clinical conditions, including neurodegenerative diseases, metabolic disorders, and muscle diseases. Understanding the role of mitochondrial markers, such as CCO, is essential for diagnosing and managing these conditions.
**Correct Answer:** C. Cytochrome C Oxidase (CCO)