Fluoride inhibits which enzyme
**Core Concept**
Fluoride is a halogen that plays a crucial role in dental health by preventing tooth decay. However, its mechanism of action involves the inhibition of an enzyme essential for bacterial metabolism. This enzyme is a key player in the breakdown of carbohydrates by certain oral bacteria.
**Why the Correct Answer is Right**
Fluoride inhibits the enzyme enolase, which is a glycolytic enzyme crucial for the anaerobic glycolysis pathway. Enolase catalyzes the conversion of 2-phosphoglycerate to enolpyruvate in the glycolytic pathway. By inhibiting enolase, fluoride disrupts the energy metabolism of bacteria, ultimately leading to their death and reducing the risk of tooth decay. This inhibition is particularly effective against Streptococcus mutans, a major contributor to dental caries.
**Why Each Wrong Option is Incorrect**
* **Option A:** This option is incorrect because fluoride does not primarily target the enzyme phosphofructokinase, which is involved in the glycolytic pathway but not the primary target of fluoride.
* **Option B:** This option is incorrect because fluoride does not inhibit the enzyme pyruvate kinase, which is also involved in glycolysis but not the primary target of fluoride.
* **Option C:** This option is incorrect because fluoride does not target the enzyme lactate dehydrogenase, which is involved in anaerobic glycolysis but not the primary target of fluoride.
**Clinical Pearl / High-Yield Fact**
Fluoride's mechanism of action as a glycolytic inhibitor is a key factor in its effectiveness in preventing dental caries. This makes fluoride an essential component of community water fluoridation programs and fluoride toothpaste.
**Correct Answer: C. Enolase**