Which of the following is a melanising agent?
**Core Concept**
The question is testing knowledge of melanin synthesis and the role of various agents in the melanisation process. Melanin is a pigment responsible for skin and hair color, produced through the action of the enzyme tyrosinase.
**Why the Correct Answer is Right**
The correct answer is a melanising agent because it acts as a substrate for the enzyme tyrosinase, facilitating the production of melanin. Tyrosinase catalyzes the conversion of tyrosine to dopachrome, which is then converted to melanin. This process is crucial for skin and hair pigmentation. The correct answer is a key player in this pathway.
**Why Each Wrong Option is Incorrect**
**Option A:** Not a significant contributor to melanin synthesis.
**Option B:** Actually, an inhibitor of tyrosinase, which would decrease melanin production.
**Option C:** Not directly involved in the melanisation process.
**Clinical Pearl / High-Yield Fact**
Remember that tyrosinase inhibitors, such as hydroquinone, are used in dermatology to reduce melanin production and treat hyperpigmentation disorders like melasma.
**Correct Answer: C. Dopa**