Total number of dehydrogenases in Kreb’s cycle

**Core Concept**
The Krebs cycle, also known as the citric acid cycle or tricarboxylic acid (TCA) cycle, is a key metabolic pathway that generates energy through the oxidation of acetyl-CoA derived from carbohydrates, fats, and proteins. It involves a series of eight enzyme-catalyzed reactions that ultimately produce NADH, FADH2, and ATP.

**Why the Correct Answer is Right**
The Krebs cycle contains three types of dehydrogenases: isocitrate dehydrogenase, alpha-ketoglutarate dehydrogenase, and succinate dehydrogenase. These enzymes catalyze the oxidation of their respective substrates, resulting in the production of NADH or FADH2. The correct answer is based on the understanding of the enzymatic reactions involved in the Krebs cycle.

**Why Each Wrong Option is Incorrect**
* **Option A:** This option is incorrect as it does not accurately represent the number of dehydrogenases in the Krebs cycle.
* **Option B:** This option is incorrect as there are not seven dehydrogenases in the Krebs cycle.
* **Option D:** This option is incorrect as there are not six dehydrogenases in the Krebs cycle.

**Clinical Pearl / High-Yield Fact**
The Krebs cycle is a crucial metabolic pathway that is essential for energy production in cells. Understanding the enzymes and reactions involved in the Krebs cycle is essential for grasping various aspects of metabolism, including the production of ATP, NADH, and FADH2.

**Correct Answer:** C. 3