Photosynthetic pigments

Photosynthetic pigments, sources and their importance.

1. PHOTOSYNTHETIC PIGMENTS SARAH HAMID M.Sc BIOTECHNOLOGY PGY-1

2. WHAT IS PHOTOSYNTHESIS? Plants are experts at capturing light energy and using it to make sugars through a process called photosynthesis.

3. WHAT IS A PIGMENT? The process of photosynthesis begins with the absorption of light by specialized organic molecules, called pigments.

4. PIGMENTS REQUIRED FOR PHOTOSYNTHESIS Chlorophyll a  is the core pigment that absorbs sunlight for light dependent photosynthesis. Accessory pigments such as:  chlorophyll b ,  carotenoids ,  xanthophylls  and  anthocyanins  lend a hand to chlorophyll a molecules by absorbing a broader spectrum of light waves.

5. ROLE OF CHLOROPHYLL IN PHOTOSYNTHESIS

6. STRUCTURE OF CHLOROPHYLL A Structurally, chlorophyll molecules include a hydrophobic ("water-fearing") tail that inserts into the thylakoid membrane and a  porphyrin ring  head (a circular group of atoms surrounding a magnesium ion) that absorbs light.

7. ACCESSORY PIGMENTS OF PHOTOSYNTHESIS The use of accessory pigments allows a broader range of wavelengths to be absorbed, and thus, more energy to be captured from sunlight. CHLOROPHYLL B Chlorophyll b transmits green light and mainly absorbs blue and red light. It captures the light energy from the sun and hands it over to chlorophyll a.

8. CAROTENOIDS Carotenoids are another key group of pigments that absorb violet and blue-green light. These are found in red of tomato (lycopene), the yellow of corn seeds (zeaxanthin), or the orange of an orange peel (β-carotene).

9. XANTHOPHYLL Xanthophyll pigments pass along light energy to chlorophyll a and act as antioxidants.  These pigments also protect plants against photodamage. These pigments produce the yellow color in fall leaves.

10. Anthocyanin pigments absorb blue-green light and aid chlorophyll a. Apples and autumn leaves owe their vibrancy to reddish, violet anthocyanin compounds. 

11. WHAT ARE ANTENNA PIGMENTS? Photosynthetic pigments like chlorophyll b and carotenoids bond with protein to form a tightly packed antenna-like structure to capture incoming photons.   Antenna pigments absorb radiant energy . These pigments pump photons into reaction centers during photosynthesis.

12. WHERE ARE THESE PHOTOSYNTHETIC PIGMENTS FOUND? PIGMENTS LOCATED IN Chlorophyll - Chloroplast Carotenoids - Chloroplast Anthocyanin - Cell vacuole Xanthophyll - Chloroplast

13. HOW DO THESE PIGMENTS WORK IN PHOTOSYNTHESIS? Chlorophyll are green substance in producers that traps light energy from the sun, which is then used to combine carbon dioxide and water into sugars in the process of photosynthesis. Chlorophyll a is the primary pigment of photosynthesis, trapping the light energy and emitting high energy electrons into the two photosystems P680 and P700. Chlorophyll b is the accessory pigment, passing the trapped energy into chlorophyll a. Accessory pigments help plants absorb additional light. MORE PIGMENTS = MORE FOOD(GLUCOSE)

14. IMPORTANCE OF PHOTOSYNTHETIC PIGMENTS = = = Pigments helps in growth and development of plants. Pigments also protect plants from damage caused by UV and visible light. Pigments act as visible signals to attract insects, birds and animals for pollination and seed dispersal.

15. CONCLUSION Plant have different pigments like chlorophyll a,b , xanthophyll, carotenoids, anthocyanins, etc. These pigments are required for the photosynthesis. All the living organisms are dependent on the process of photosynthesis (produces glucose and oxygen) either directly or indirectly. Chlorophyll a is the core/main photosynthetic pigment the rest being accessory. Chlorophyll is vital for photosynthesis, which helps plants get energy from light.