Which among the following secondary metabolites is a lectin?

Options

A. Morphine
B. Monoterpene
C. Concanavalin A
D. Curcumin

Answer

To solve the question "Which among the following secondary metabolites is a lectin?" we can follow these steps:

### Step 1: Understand the Definitions
- **Primary Metabolites**: These are compounds that are directly involved in the normal growth, development, and reproduction of organisms. Examples include amino acids, sugars, and nucleotides.
- **Secondary Metabolites**: These are organic compounds that are not directly involved in the normal growth, development, or reproduction of an organism. They often have ecological functions, such as defense mechanisms or attracting pollinators.

### Step 2: Identify the Options
The options given are:
1. Morphine
2. Monoterpene
3. Concanavalin A
4. Curcumin

### Step 3: Classify Each Option
- **Morphine**: This is an alkaloid, a type of secondary metabolite.
- **Monoterpene**: This falls under terpenoids, another class of secondary metabolites.
- **Concanavalin A**: This is a type of lectin, which is a carbohydrate-binding protein.
- **Curcumin**: This is a polyphenolic compound, often found in turmeric, and is also classified as a secondary metabolite.

### Step 4: Identify the Lectin
Among the options, we need to identify which one is a lectin.
- **Lectins** are proteins that bind to carbohydrates and are often involved in various biological processes, including cell-cell recognition and signaling.

### Step 5: Conclusion
From the analysis, **Concanavalin A** is identified as a lectin. Therefore, the correct answer is:

**C. Concanavalin A**