Which of the following is an accurate description of carotenoids?

• A. Carotenoids are proteins that transport electrons in the thylakoid membrane.
• B. Carotenoids are accessory pigments that absorb light energy and protect chlorophyll from photo-damage.
• C. Carotenoids are enzymes that catalyze the fixation of carbon dioxide during photosynthesis.
• D. Carotenoids are the primary pigments responsible for the green color of leaves.

Answer: (B)

Verified step by step guidance

1. Step 1: Begin by understanding the term 'carotenoids.' Carotenoids are organic pigments found in plants, algae, and photosynthetic bacteria. They play a role in photosynthesis and are responsible for the yellow, orange, and red colors in many organisms.
2. Step 2: Evaluate the first option: 'Carotenoids are proteins that transport electrons in the thylakoid membrane.' This is incorrect because carotenoids are pigments, not proteins, and their primary role is not electron transport.
3. Step 3: Evaluate the second option: 'Carotenoids are accessory pigments that absorb light energy and protect chlorophyll from photo-damage.' This is accurate because carotenoids absorb light energy in wavelengths that chlorophyll cannot and help prevent oxidative damage to chlorophyll molecules.
4. Step 4: Evaluate the third option: 'Carotenoids are enzymes that catalyze the fixation of carbon dioxide during photosynthesis.' This is incorrect because carotenoids are pigments, not enzymes, and they do not directly participate in carbon fixation.
5. Step 5: Evaluate the fourth option: 'Carotenoids are the primary pigments responsible for the green color of leaves.' This is incorrect because chlorophyll is the primary pigment responsible for the green color of leaves, not carotenoids.