Detailed note on chlorophyll.

1. STRUCTURE OF
CHLOROPHYLL,CHLOROPLAST
&
PHOTOSYSTEM 1 AND 2
SUBMITTED BY
SHEFI VARGHESE
1ST M.Sc FTQA
MRC,MUNNAR

2. Chlorophyll is a green compound found in leaves
and green stems of plants.
chlorophyll was a mixture of two compounds,
chlorophyll-a and chlorophyll-b.
Chlorophyll is remarkably similar in structure to
hemoglobin.
Chlorophyll is found in virtually all photosynthetic
organisms, including green plants, cyanobacteria,
and algae. It absorbs energy from light; this
energy is then used to convert carbon dioxide to
carbohydrates.

3. 1. Chemically,chlorophylls are complex
magnesium-pyrrole derivatives.
2. The chlorophyll molecule consist of a
central metal core ie, magnesium
surrounded by a nitrogen- containing
structure resulting in a porphyrin ring.
3. A number of side chains atached to
the ring structure,of which an
important one is , the side chain of a
long hydrocarbon called phytol ring
3. Chemical formula:- C55H72MgN4O5

5. Main site of photosynthesis in plants.
Chiefly occur in the mesophyll of cells.
Food producers of plants.
Chloroplast is found in all higher plants.
They are double membrane organelle with the presence
of outer,inner and intermembrane space.
2 distinct regions are present:- Grana and Stroma

6. a. Membrane envelope
b. intermembrane space
c. Thylakoid system
d. stroma
e. Grana
f. Chlorophyll

7. • The light absorbing photosynthetic pigments are arranged on the
thylakoid membranes of chloroplast in two interacting
complexes,called pigment systems or photosystems.
• There are 2 types :- Photosystem 1(mainly present in unstacked
membrane)and Photosystem 2(mainly in stacked membranes).
• Each photosystem consist of many thousand photosynthetic units
called quantasomes

8. • Quantasomes are closely packed
arrays of spherical or oblate granular
particles ,regularly arranged on or in
chloroplast thylacoids.
• Light harvesting functional units of
chloroplast,capable of carrying out
photochemical reactions.
• In green plants,each quatasomes
consist of 200-400 chlorophyll
molecules and many accessory
pigments molecules,all associated

9. Photosystem- I
• Involved in both cyclic and non-
cyclic photophosphorylations.
• Receives eectrons from PS-1 and
PS-2 and forms a strong reductant
which reduces NADP to NADPH +
H.
• Not involved in the photolysis of
water and the release of oxygen.
• the reaction centre is P700.
• The absorption peak of the reaction
centre is at 700nm.
Photosystem -II
• Involved only in non cyclic
photophosphorylation
• Donates electrons to PS-1 for
reducing NADP to NADPH + H
• Involved in the photolysis of water
and the release of oxygen.
• The reaction centre is P680
• The absorption peak of the reaction
centre is at P680nm.

10. reference
• Britannica, T. Editors of Encyclopaedia (2022, August 31).
chlorophyll. Encyclopedia Britannica.
https://www.britannica.com/science/chlorophyll