Which of the following pigments are involved in free
**Core Concept**
The question is testing the student's knowledge of the pigments involved in free radical scavenging and antioxidant defense mechanisms in the body.
**Why the Correct Answer is Right**
Melanin, bilirubin, and uric acid are all pigments that have antioxidant properties and can scavenge free radicals, thereby protecting cells from oxidative damage. Melanin, in particular, is a potent antioxidant found in the skin, eyes, and brain, and has been shown to protect against UV radiation-induced damage. Bilirubin, a byproduct of heme catabolism, has been found to have anti-inflammatory and antioxidant properties, and has been implicated in the pathogenesis of various diseases. Uric acid, a waste product of purine metabolism, has antioxidant properties and can scavenge free radicals, although its role in disease is complex and multifaceted.
**Why Each Wrong Option is Incorrect**
* **Option A:** This option is incorrect because while it may be involved in some antioxidant processes, it is not a pigment involved in free radical scavenging.
* **Option B:** This option is incorrect because it is a pigment involved in photosynthesis and is not directly related to free radical scavenging in the body.
* **Option C:** This option is incorrect because it is a type of fiber and does not have antioxidant properties.
**Clinical Pearl / High-Yield Fact**
Melanin is a key player in protecting the skin from UV radiation-induced damage, and its antioxidant properties are thought to contribute to its protective effects.
**Correct Answer:** C. Uric acid