Page 1
Plant Pigments
Institute of Lifelong Learning, University of Delhi
1
Discipline: Botany
Paper: Plant physiology
Lesson: Plant Pigments
Lesson Developer: Ms. Dhara Arora
Department/College: Department of Botany,
University of Delhi
Page 2
Plant Pigments
Institute of Lifelong Learning, University of Delhi
1
Discipline: Botany
Paper: Plant physiology
Lesson: Plant Pigments
Lesson Developer: Ms. Dhara Arora
Department/College: Department of Botany,
University of Delhi
Plant Pigments
Institute of Lifelong Learning, University of Delhi
2
Table of contents
Lesson: Plant pigments
? Introduction
? Carotenoids
? Flavonoid/ Anthocyanins
? Chlorophylls
? Betalains
? Summary
? Exercise/ Practice
? Glossary
? References/ Weblinks
Page 3
Plant Pigments
Institute of Lifelong Learning, University of Delhi
1
Discipline: Botany
Paper: Plant physiology
Lesson: Plant Pigments
Lesson Developer: Ms. Dhara Arora
Department/College: Department of Botany,
University of Delhi
Plant Pigments
Institute of Lifelong Learning, University of Delhi
2
Table of contents
Lesson: Plant pigments
? Introduction
? Carotenoids
? Flavonoid/ Anthocyanins
? Chlorophylls
? Betalains
? Summary
? Exercise/ Practice
? Glossary
? References/ Weblinks
Plant Pigments
Institute of Lifelong Learning, University of Delhi
3
Learning outcomes:
The student will be able to
? Learn about the principal plant pigments
? Learn about various kinds of pigments and their occurrence in plants
? Understand Structures and biosynthetic pathway of carotenoids
? Understand role of carotenoids present in plants
? Understand types of flavonoids and their biological significance
? Learn about anthocyanins and their uses
? Understand the structure of chloroplasst
? Understand the significant role of chlorophylls in photosynthesis
? Explain the entire biosynthetic pathway of betalains
? Learn about the properties and applications of betalains
Page 4
Plant Pigments
Institute of Lifelong Learning, University of Delhi
1
Discipline: Botany
Paper: Plant physiology
Lesson: Plant Pigments
Lesson Developer: Ms. Dhara Arora
Department/College: Department of Botany,
University of Delhi
Plant Pigments
Institute of Lifelong Learning, University of Delhi
2
Table of contents
Lesson: Plant pigments
? Introduction
? Carotenoids
? Flavonoid/ Anthocyanins
? Chlorophylls
? Betalains
? Summary
? Exercise/ Practice
? Glossary
? References/ Weblinks
Plant Pigments
Institute of Lifelong Learning, University of Delhi
3
Learning outcomes:
The student will be able to
? Learn about the principal plant pigments
? Learn about various kinds of pigments and their occurrence in plants
? Understand Structures and biosynthetic pathway of carotenoids
? Understand role of carotenoids present in plants
? Understand types of flavonoids and their biological significance
? Learn about anthocyanins and their uses
? Understand the structure of chloroplasst
? Understand the significant role of chlorophylls in photosynthesis
? Explain the entire biosynthetic pathway of betalains
? Learn about the properties and applications of betalains
Plant Pigments
Institute of Lifelong Learning, University of Delhi
4
Introduction
Pigments are the molecules which absorb light energy in the wavelength range
of visible region. Upon absorption of light by a pigment molecule, the energy of
absorbed photon is transferred to the electron. Chromophore (molecule-specific
structure) captures the energy and excites the electron, due to which it jumps to
a higher orbital. The non-absorbed energy is reflected and/or refracted back,
captured by the eye and generates neural impulses, which are interpreted as
color in the brain. The absorbed light can be used by the plant for chemical
reactions.
On the basis of origin, pigments can be classified as natural, synthetic, or
inorganic. A variety of different kinds of molecules constitute the plant pigments
such as, chlorophylls, flavonoids, porphyrins, carotenoids, phycobilins,
anthocyanins and betalains, etc. All biological pigments selectively absorb
certain wavelengths of light while reflecting others.
Page 5
Plant Pigments
Institute of Lifelong Learning, University of Delhi
1
Discipline: Botany
Paper: Plant physiology
Lesson: Plant Pigments
Lesson Developer: Ms. Dhara Arora
Department/College: Department of Botany,
University of Delhi
Plant Pigments
Institute of Lifelong Learning, University of Delhi
2
Table of contents
Lesson: Plant pigments
? Introduction
? Carotenoids
? Flavonoid/ Anthocyanins
? Chlorophylls
? Betalains
? Summary
? Exercise/ Practice
? Glossary
? References/ Weblinks
Plant Pigments
Institute of Lifelong Learning, University of Delhi
3
Learning outcomes:
The student will be able to
? Learn about the principal plant pigments
? Learn about various kinds of pigments and their occurrence in plants
? Understand Structures and biosynthetic pathway of carotenoids
? Understand role of carotenoids present in plants
? Understand types of flavonoids and their biological significance
? Learn about anthocyanins and their uses
? Understand the structure of chloroplasst
? Understand the significant role of chlorophylls in photosynthesis
? Explain the entire biosynthetic pathway of betalains
? Learn about the properties and applications of betalains
Plant Pigments
Institute of Lifelong Learning, University of Delhi
4
Introduction
Pigments are the molecules which absorb light energy in the wavelength range
of visible region. Upon absorption of light by a pigment molecule, the energy of
absorbed photon is transferred to the electron. Chromophore (molecule-specific
structure) captures the energy and excites the electron, due to which it jumps to
a higher orbital. The non-absorbed energy is reflected and/or refracted back,
captured by the eye and generates neural impulses, which are interpreted as
color in the brain. The absorbed light can be used by the plant for chemical
reactions.
On the basis of origin, pigments can be classified as natural, synthetic, or
inorganic. A variety of different kinds of molecules constitute the plant pigments
such as, chlorophylls, flavonoids, porphyrins, carotenoids, phycobilins,
anthocyanins and betalains, etc. All biological pigments selectively absorb
certain wavelengths of light while reflecting others.
Plant Pigments
Institute of Lifelong Learning, University of Delhi
5
Figure: Some Major plant pigments
Source:Author
Some major plant pigments, their types and occurence
Pigments Common types Occurrence color
Chlorophylls Chlorophyll a, b Green plants Green
Carotenoids
Carotenes and
xanthophylls
Bacteria. Green plants
(masked by chlorophyll),
vegetables (carrots), fruits
(mangoes).
Orange, red,
yellow, pink
Flavonoids
Anthocyanins, aurones,
chalcones, flavonols and
proanthocyanidins
color production in flowers.
Common in plants such as
berries, citrus fruits, etc.
Yellow, red,
blue, purple
Betalains
Betacyanins and
betaxanthins
Flowers and fungi
Red to violet,
also yellow to
orange
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