Membrane bound Krebs cycle enzyme is

Options

A. Fumarase
B. Cis-aconitase
C. Succinic dehydrogenase
D. Malate dehydrogenase.

Answer

To determine which enzyme in the Krebs cycle is membrane-bound, we can follow these steps:

### Step 1: Understand the Krebs Cycle
The Krebs cycle, also known as the citric acid cycle or TCA cycle, is a series of enzymatic reactions that take place in the mitochondria. It is crucial for cellular respiration and energy production.

### Step 2: Identify the Enzymes
The question provides four options:
A. Fumarase
B. Succinic Dehydrogenase
C. Malate Dehydrogenase
D. Cisconutase

### Step 3: Determine Membrane-Bound Enzymes
Among the enzymes listed, we need to identify which one is associated with the mitochondrial membrane.

### Step 4: Analyze Each Option
- **Fumarase**: This enzyme catalyzes the conversion of fumarate to malate and is not membrane-bound.
- **Succinic Dehydrogenase**: This enzyme is known to be embedded in the inner mitochondrial membrane and is involved in both the Krebs cycle and the electron transport chain (ETC). It catalyzes the conversion of succinate to fumarate.
- **Malate Dehydrogenase**: This enzyme catalyzes the conversion of malate to oxaloacetate and is also not membrane-bound.
- **Cisconutase**: This enzyme is not a standard term in the Krebs cycle and is likely a misnomer.

### Step 5: Conclusion
Based on the analysis, the only enzyme that is membrane-bound and participates in the Krebs cycle is **Succinic Dehydrogenase**.

### Final Answer
The membrane-bound Krebs cycle enzyme is **C. Succinic Dehydrogenase**.

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