Question

Which chlorophyll does not possess phytol?
a. Chlorophyll a
b. Chlorophyll b
c. Chlorophyll c
d. Chlorophyll d

Answer 1

Hint: Chlorophyll is a photosynthetic pigment that is usually found in photosynthetic organisms. The chlorophyll absorbs the energy in the form of light from the sun and converts it into chemical energy which is used by plants.

Complete answer:
The chlorophyll is a photosynthetic pigment found in organelles called chloroplasts which carry out photosynthesis in plants, algae and cyanobacteria. Chlorophylls absorb light mostly of blue and red wavelength and are a very poor absorber of the green portion of the spectrum that is why it reflects green color. Chlorophylls are of four types: chlorophyll a, b, c and d.

Chlorophylls contain porphyrins; the head contains a tetra-pyrrole ring that has a chelate metal ion in their core and a hydrocarbon chain called phytol tail. The metal ion present in the core is magnesium.
> Chlorophyll a: It is the primary pigment of photosynthesis and is found in almost all photosynthetic organisms. It absorbs light in orange to red and violet to blue spectrum for carrying out photosynthesis.

> Chlorophyll b: Although it is one of the main pigments of photosynthesis but chl b acts more as an accessory pigment with chl a. Also, it may be absent in some organisms. It absorbs the light of blue color and increases the amount of food produced as compared to plants with only chl a. The presence of chl b in some plants is the strategy for the plants that habitat the regions with low availability of sunlight.

> Chlorophyll c: It is present in the organisms belonging to algae and some prokaryotes. –chl c occurs with other pigments in nature (for example with chl a and carotenoids). Also, chl c also differs in structure among all the four chlorophylls. Chl c lacks the phytol tail in its porphyrins structure. This chlorophyll is mostly seen in algae inhabiting marine and freshwater.

> Chlorophyll d: It is a minor pigment which absorbs the light that falls in the red spectrum. It is found in red algae and cyanobacteria. Also, these have some minor differences from chl a, chl b, and chl c.

Hence, The correct answer is option (C).

Note: There are many pigments that work in conjugation with main pigments and are called accessory pigments. These include chlorophyll b, chlorophyll c and chlorophyll d which are found in higher plants and algae. In addition to this, there are non-chlorophyll pigments that absorb the light energy and transfer it to the photosystem in chlorophyll example: carotenoids and phycobilins.