This document presents information on plant pigments and their roles. It discusses that pigments absorb specific wavelengths of light and reflect others, giving them their color. The primary pigments in plants are chlorophyll, carotenoids, xanthophylls, anthocyanins, and betalins. Chlorophyll is the main photosynthesis pigment and absorbs blue and yellow light, reflecting green. Carotenoids and xanthophylls help capture light not absorbed by chlorophyll. Anthocyanins provide red to blue colors and betalins provide red or yellow colors. Together, plant pigments perform vital functions in photosynthesis, attracting pollinators, and providing anti-oxidant benefits.

1. TERM PAPER PRESENTATION
BTY 105: PRINCIPLES OF BIOCHEMISTRY
TOPIC: PLANT PIGMENTS AND THEIR ROLE
Submitted to:
Dr. Kuldip Chandra Verma
Deptt. Of Biotechnology
Lovely Professional University
Submitted by:
Vir Sapan Pratap Anand
11202530
Section : B1205
Roll No. : A07

2. INTRODUCTION: WHAT ARE PIGMENTS ?
Pigments are “molecules that absorb specific
wavelength (energies) of light and reflect all others.”
 Pigments are coloured.
 The colour we see is the net effect of all the light
reflecting back at us…!
 They are the substances produced by living
organisms that have a colour resulting from
selective colour absorption.


3. WHAT DO I MEAN BY “ABSORB” ?
Electrons exist at specific levels
 Normally exist at lowest specific levels
 However, if enough energy comes to boost them
into the next level, they can ABSORB that
energy…!!! And occupy that higher level.


4. WHAT DO I MEAN BY “ABSORB” ?
(CONT…)
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The light they absorb contains just the right amount of energy
to push them into the next level.
Light not having enough energy or having too much energy is
reflected back…!!!
Electron does not want to stay at higher level
It wants to return because it is unstable there.
Inorder to do this it has to release energy that has put it into
higher level.

5. WAYS TO RELEASE ENERGY ??
By heat: Conversion in molecular motion
 By fluorescence: Losing e- by light
 By Resonance: The energy but not the e- itself can
be passed on to another molecule.
 By transferring the electron to another molecule
-------------------- Plant pigments usually utilize the last two of these
reactions to convert the sun’s energy into their own.


6. BIOLOGICAL PIGMENTS
Produced by living organisms.
 Have a colour resulting from selective colour
absorption.
 Include “Plant pigments” and “Flower pigments.”
 Biological structures such as

Skin
Eyes
Fur
Hair
Contain “melanin” pigment in specialized cells called
“chromatophores”.

7. PIGMENT COLOUR V/S STRUCTURAL
COLOUR
Pigments colour differs from structural colour.
 Pigment colour: “Same for all viewing angles”.
 Structural colour: “ Result of selective reflection or
iridescence, usually because of multilayer structure.
 For example butterfly wings typically contain
structural colour, although many butterflies have
cells that contain pigment as well.


8. TYPES OF BIOLOGICAL PIGMENTS
1. Heme/Porphyrin based: Chlorophyll, bilirubin,
hemoglobin, myoglobin.
2. Light Emitting: Luciferin
3. Carotenoids:
i)
Hematochromes : Algal pigments, mixes of
carotenoids and their derivatives.
ii)
Carotenes: alpha and beta Carotene
iii)
Xanthophylls: Oxidised Carotenes (Eg.
Canthaxanthin)
4. Proteinaceous : Phytochrome
5. Polyene enolates: A class of red pigments unique to
parrots
6. Other: Melanin, Urochrome, flavanoids

9. PIGMENTS IN PLANTS-:
The Principal pigments in plants are-:
1. Chlorophyll
2. Carotenoids
3. Xanthophylls
4. Anthocyanins
5. Betalins

10. PRIMARY FUNCTION OF PIGMENTS IN
PLANTS:Primary Function : Photosynthesis
 Uses green pigment chlorophyll along with several
red and yellow pigments.
 Help to capture as much light as possible.
 Other functions include attracting insects to flowers
to encourage pollination.


11. CHLOROPHYLL
Primary pigment in plant.
 Chlorin absorbs yellow and blue wavelengths.
 Reflecting green.
 All land plants and green algae have two types of
chlorophyll.
 Chlorophyll a and Chlorophyll b.
 Kelps and photosynthetic heterokonts contain
Chlorophyll c.
 Chlorophyll serve as fuel to photosynthesis.


12. STRUCTURE OF CHLOROPHYLL

13. MORE ABOUT CHLOROPHYLL-:
Name derived from greek words
 Chloros means “green” and phyllon means “leaf”.
 Synthesized from succinyl-CoA and Glycine.
 Immediate precursor to Chlorophyll A and B is
protochlorophyllide.
 Contains hydrophobic phytol chain embedded in
lipid membrane.
 Rest structure is tetrapyrrolic ring.
 It is the part of pigment that absorbs the energy
from light.
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14. CHLOROPHYLL AND PHOTOSYNTHESIS
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Autotrophic Process: Plants and plant-like organisms make
their energy (glucose) from sunlight.
Stored as carbohydrate in their bodies.
6CO2 + 6H2O + sunlight  C6H12O6 + 6O2
Makes organic molecules (glucose) out of inorganic materials
(carbon dioxide and water).
It begins all food chains/webs. Thus all life is supported by
this process.
It also makes oxygen gas!!

15. WHY ONLY GREEN AND NOT BLACK ??
Black Colour is the best absorber of light.
 Then why couldn’t plants evolve this change ?
 Plants except some red algae appear brown or
green but not black. Why ?
 If plants had pigments that absorbed UV and XRays, this would mean that electrons could be
knocked off their orbitals and the molecule
destroyed.
 If plants absorbed IR and Radio waves, there would
not be enough energy for electron transfer, just
enough to warm up the molecule.


16. CAROTENOIDS:
Red, orange or yellow pigments.
 Function as accessory pigments in plants.
 Absorb wavelength not readily absorbed by
chlotophyll.
 Ex: Carotene ( Found in Carrots)
 Lutein ( Yellow pigment found in fruits and
vegetables).
 Lycopene ( Red pigment in tomatoes)
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17. ROLE OF CAROTENOIDS
Attract pollinators and seed dispersers
 Accessory photosynthetic Pigment in periods of
low light,
 Absorbs excess light energy,
 Anti oxidant roles,
 Substrate for hormones
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18. CAROTENOIDS:
Carotenoids are Present in:
Carrot,
 Sweet potato,
 Winter squash,
 Pumpkin,
 Green leafy vegetables,
 Cantaloupe,
 Apricot
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19. ANTHOCYANINS:
Literally “Flower blue”
 Water soluble flavanoid pigments
 Colour appear as red to blue, acc to pH.
 Occur in all tissues of higher plants but colour not
noticeable.
 Have purple colur and are present in:
 vegetables
 (onions, cabbage, potatoes), red, blue & purple
berries, black beans


20. ROLE OF ANTHOCYANINS:
 attract
pollinators and seed dispersers
 repel predators, protect cells from damage
by excess light,
 improve plant tolerance to stress such as
drought, U V-B,
 improve night vision and other vision
 disorders, protect against heart disease,

21. BETALINS
Red or yellow pigments.
 Water soluble.
 Synthesized from tyrosine.
 Never co-occur in plants having anthocyanins.
 Occur in:
 beets (red and yellow ), chard, spinach, fruit of
prickly-pear cactus.
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22. ROLE OF BETALINS
Anti oxidant,
 May protect against heart disease,
 various cancers,
 ulcers,
 liver damage
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23. XANTHOPHYLLS
 Fourth
common class of pigments
 Essentially oxidized carotenes
 Usually red and yellow
 Do not absorb energy as well as
carotenoids.

24. CONCLUSION:
Life would be nothing without Plants…
 And Plants would be nothing without colours…
 Green plants having chlorophyll have a vital role in
photosynthesis, a process neccessary for life on
earth.
 Red and yellow plants and flowers having
carotenoids or Betalins provide fresh fruits, and
help in pollination.
 Blue plants and flowers having Anthocyanins are
strong anti-oxidants.
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25. ANY QUERIES ??