What are carotenoids?
Q: What are carotenoids?
A: Carotenoids are organic pigments found in the chloroplasts and chromoplasts of plants, and also some bacteria and fungi.
Q: How many types of carotenoids are there?
A: There are two types of carotenoids - xanthophylls, which contain oxygen, and carotenes, which are purely hydrocarbons with no oxygen.
Q: What are the two key roles of carotenoids in plants and algae?
A: The two key roles of carotenoids in plants and algae are to absorb light energy for use in photosynthesis, and to protect chlorophyll from photodamage.
Q: What are the only animals known to produce carotenoids?
A: The only animals known to produce carotenoids are aphids and mites, which got the genes from fungi.
Q: What is the most common form of carotenoids in plants?
A: Beta-carotene is the most common form of carotenoids in plants.
Q: Do some carotenoids have vitamin A activity?
A: Yes, some carotenoids like β-carotene have vitamin A activity, which means they can convert to retinol.
Q: How do certain carotenoids protect the eye?
A: Certain carotenoids like lutein, astaxanthin, and zeaxanthin act directly to absorb damaging blue and near-ultraviolet light, protecting the macula of the retina, the part of the eye with the sharpest vision.
