CA) Chlorophylls Chlorophyl DH2 oP, p") Chlorophyll a
Chlorophyll ➢ Embedded in the thylakoid membranes. ➢ Absorbs light strongest in the violet/blue and red wavelengths. Reflect green light. ➢ Chlorophyll a– occurs in all photosynthetic eukaryotes and cyanobacteria. Main pigment responsible for transforming light into chemical energy
Accessory Pigments Chlorophyll b
Accessory Pigments ➢ Pigments not directly involved in photosynthetic energy transduction in the reaction center. •They capture light energy of different wavelengths and then pass the energy to chlorophyll a in the reaction center. ➢ Chlorophyll b - plants, green algae, and euglenoid algae. ➢ Chlorophyll c - some groups of algae
Accessory Pigments 口 Carotenoids(米胡卜
Accessory Pigments ❑ Carotenoids (类胡萝卜素)-- ➢ Embedded in the thylakoid membranes. ➢ Also serve a critical function in preventing photooxidative damage to chlorophyll (antioxidant). ➢ Two groups • Carotenes – Beta -carotene is a key source of vitamin A. • Xanthophylls – Anti-oxidants. Accessory Pigments ❑ Phycobillins (billinpigments)– cyanobacteria & red algae. • Water soluble
OH B H A‖c O- St OH Anthocyanin
Another Pigment ➢ Anthocyanins (花青素)- flower petal color. • Stored in the vacuole. • Not involved in photosynthesis. ➢ Not an Accessory Pigment
Bacteriochlorophyll a <Chlorophyll b Taiz Zeiger 2002 used with permission Chlorophyll a Phycoerythrobilin o 5 carotene 400 500 600 700 800 Wavelength(nm) visible spectrum Infrared