Role Of Plant Pigments In Photosynthesis PDF

Why are most plants green in color? We noticed that most plants around us are green in color, but not all. Green plants are green because they contain a coloring molecule called chlorophyll. Chlorophyll is the light harvesting pigment inside the chloroplast. What is Chlorophyl...

Why are most plants green in color? We noticed that most plants around us are green in color, but not all. Green plants are green because they contain a coloring molecule called chlorophyll. Chlorophyll is the light harvesting pigment inside the chloroplast. What is Chlorophyll? Chlorophyll: Plant pigment responsible for the green color of plants. Found in chloroplasts, the structures in plant cells. Enables plants to trap light energy from the sun. Converts light energy into chemical energy usable by plants and animals. Absorbs light energy to synthesize carbon dioxide and water into glucose and oxygen. The food molecules produced provide chemical energy for cellular functions. This process is known as photosynthesis—the method by which plants and other organisms make food. What is Chlorophyll? Chlorophyll is found inside the Thylakoid of the Chloroplast What are other pigments found in plants? Plants exhibit various colors due to different pigments. Chlorophyll: Primary green pigment. Carotenoids: Reflect red, orange, or yellow colors, absorb blue-green light. Xanthophylls: Reflect yellow or brown, absorb blue-violet light. These accessory pigments assist in photosynthesis (Audesirk, 2003; Campbell, 2003). Photosynthetic Pigments in Plants and Other Phototrophic Organisms 2 Main Photosynthetic Pigments: q Principal Pigments ü Chlorophyll A ü Bacteriochlorophyll q Accessory Pigments ü Chlorophyll B ü Carotene ü Chlorophyll C and D ü Xanthophyll ü Carotenoids ü Phycoerythrin ü Phycobilins ü Phycocyanin Chlorophyll A Absorbs blue-violet and red lights; Reflects green light. Found in all plants Bacteriochlorophyll Absorbs the lights in the infrared region. Reflects reddish - purple lights Found in phototrophic bacteria Chlorophyll B Absorbs blue and orange lights; Reflects yellow - green lights Found in plants, multi- celled algae and single-celled algae (diatoms) Chlorophyll C and D Absorbs red and blue lights; Reflects yellow - green lights Found in plants, multi- celled algae and single-celled algae (diatoms) Carotenoids (Carotene) Absorbs blue, violet lights; Reflects red, orange lights Found in All Plants Carotenoids (Xanthophyll) Absorbs blue, violet lights; Reflects brown, yellow lights Found in All Plants Phycobilins (Phycoerythrin) Absorbs dim and blue lights; Reflects red light Found in red algae Phycobilins (Phycocyanin) Absorbs orange and red lights; Reflects blue light Found in cyanobacteria Photosynthetic Pigments in Plants and Other Phototrophic Organisms Photosynthetic Pigments Light Absorbed and Reflected Found in Chlorophyll a Absorbs blue-violet and red lights; Reflects green light all plants Absorbs the lights in the infrared Principal region (red light to violet); Reflects reddish - purple phototrophic bacteria Pigments Bacteriochlorophyll lights Absorbs blue and orange lights; Reflects yellow -green Chlorophyll b plants, multi- celled lights algae and single-celled Absorbs red and blue lights; Reflects yellow -green Chlorophyll c and d algae (diatoms) lights Absorbs blue, violet lights; Carotene Reflects red, orange lights Carotenoids Absorbs blue, violet lights; all plants Xanthophyll Reflects brown, yellow lights Accessory Absorbs dim and blue lights; Pigments Phycoerythrin Reflects red light red algae and Phycobilins Absorbs orange and red lights; Phycocyanin cyanobacteria Reflects blue light Photosynthetic Pigments in Plants and Other Phototrophic Organisms Changes of Color due to Seasons In regions with four seasons, leaves change color due to temperature drops and shorter daylight in fall. Chlorophyll breaks down, revealing hidden pigments like carotenoids (orange/yellow) and anthocyanins (brown/red).Fall leaves turn yellow or orange as photosynthesis slows. In winter, leaves appear dark orange due to carotenoids, and in spring, they darken further due to anthocyanins.  What is the role of pigments in photosynthesis? Biological pigments, also called biochromes, are molecules that give color to living things. Plant pigments are photoreceptors, absorbing sunlight and converting it into chemical energy. Chlorophyll and other pigments help transform carbon dioxide and water into glucose and oxygen during photosynthesis. These pigments enable the conversion of solar energy into chemical energy, supporting the entire food chain. How does chlorophyll transform light energy? During photosynthesis, chlorophyll Energy Incident on Leaf: and other pigments absorb light. However, only 1% of the sunlight 75% is evaporated that reaches a leaf's surface is used 15% is reflected for photosynthesis. 5% is transmitted through the leaf 4% is converted to heat energy 1% is used in photosynthesis How does chlorophyll transform light energy? Photosynthesis consists of two Light energy excites electrons, main reactions: which are carried by NADPH to the Light reaction: Chlorophyll and stroma. other pigments harvest light In the stroma, during the Calvin energy. Cycle, the energy is converted into Calvin Cycle (dark reaction): Uses ATP. the absorbed energy to convert ATP stores energy in the chemical carbon dioxide into glucose. bonds of glucose, the end product In photosynthesis, sunlight is of photosynthesis. absorbed by chlorophyll and accessory pigments in the chloroplast. How does chlorophyll transform light energy?