Which of the following pigments absorbs light and prevents photo-oxidation of chlorophyll ?

Options

A. Chlorophyll a
B. Chlorophyll b
C. Carotenoids
D. Xanthophylls

Answer

To solve the question regarding which pigment absorbs light and prevents photo-oxidation of chlorophyll, we can follow these steps:

### Step 1: Understand the Role of Pigments in Photosynthesis
Photosynthesis in plants, algae, and photosynthetic bacteria involves pigments that trap sunlight energy to synthesize sugars. The main pigments involved are chlorophyll A and B, which are found in plastids.

**Hint:** Remember that pigments are essential for capturing light energy during photosynthesis.

### Step 2: Identify the Main Pigments
Chlorophyll A and B are the primary pigments that absorb light. Chlorophyll A absorbs mainly blue and red light, while chlorophyll B absorbs light in the blue and red-orange spectrum.

**Hint:** Focus on the colors absorbed by chlorophyll A and B to understand their role.

### Step 3: Recognize the Need for Accessory Pigments
In addition to chlorophyll, plants have accessory pigments such as carotenoids and xanthophylls. These pigments help in capturing a broader range of light wavelengths, thus enhancing the efficiency of photosynthesis.

**Hint:** Accessory pigments are important for increasing the range of light absorption.

### Step 4: Understand Photo-Oxidation
Photo-oxidation refers to the damage caused to chlorophyll molecules due to excessive light. High light intensity can lead to the formation of reactive oxygen species, which can harm the chlorophyll.

**Hint:** Consider how excess light can negatively affect chlorophyll.

### Step 5: Identify the Pigment that Prevents Photo-Oxidation
Carotenoids play a crucial role in preventing photo-oxidation. They absorb excess light energy and dissipate it as heat, thus protecting chlorophyll from damage. They also scavenge toxic oxygen species generated during high light conditions.

**Hint:** Look for pigments that have protective roles against excess light energy.

### Step 6: Conclusion
Based on the understanding of the roles of different pigments, the correct answer to the question is that carotenoids are the pigments that absorb light and prevent photo-oxidation of chlorophyll.

**Final Answer:** The pigment that absorbs light and prevents photo-oxidation of chlorophyll is **carotenoids**.