1. Biology pigments hw

2. • Carotenoids
• Carotenoids are also associated with the process of photosynthesis.
Additionally, they give a bright colour to the fruits and flowers. They
are terpenoid pigments present in all photosynthetic plants and they
also occur in photosynthetic bacteria such as Rhodobacter and
Erwinia. Carotenoids are orange, red and yellow pigments that usually
occur in the roots, tubers, leaves, fruits, seeds and flowers.
• This group includes the xanthophylls (yellow pigments) and carotenes
(orange pigments).

3. • Phycobilins
• It is a light-capturing bile pigment found in the chloroplast of red
algae and cyanobacteria. They have chromatophores that are
primarily responsible for their colour. These are unique pigments as
they are bonded to water-soluble phycobiliproteins which pass
sunlight to chlorophyll and thus help in the process of photosynthesis.

4. • Flavonoids
• Flavonoids are another type of commonly-found
pigment, which are phenylpropanoid compounds.
There are several classes of flavonoids out of
which only a few provide pigments to plants
like the proanthocyanidins (condensed tannins)
and anthocyanins. Flavonoids occur in almost
all tissues. Apart from providing floral
pigmentation, they are also involved in
nitrogen fixation, physiological regulation, UV
filtration, etc.

5. • Carotenoids
• Carotenoids, a precursor of Vitamin A, are responsible for
transmitting orange, yellow and red light waves. Also called
tetraterpenoids, this pigment can be produced from plants, algae, fats
and other building blocks of the organism. They are fat-soluble
molecules that can dissipate radiant energy in excessive amounts. Its
molecular formula is C40H56 and its molecular weight is 536.9

6. • Xanthophyll
• Xanthophyll pigments act as an antioxidant by passing light energy to
chlorophyll A. It produces a yellow colour in the leaves at the fall of
the year and can donate or share electrons. Its molecular formula is
C40H56O2 with a molecular weight of 568.9

7. • Anthocyanin
• Anthocyanin is a water-soluble molecule that is stored in the plant
cell vacuole. It absorbs blue-green light and emits reddish and violet
light into the environment. Autumn leaves appear reddish in colour
due to the anthocyanin compound. Its chemical formula is
C15H11O+.

8. • Antenna pigments
• When photosynthetic pigments like chlorophyll B and carotenoids
react with protein, the resultant product is a tightly packed antenna-
like structure capable of capturing incoming photons. Antenna
pigments absorb radiant energy to pump photons into reaction
centres as a part of the photosynthetic process. It can be used for
manufacturing ATP molecules by exciting an electron with the help of
a photon and passing it to the nearby acceptor molecule.