Question

In pigment system 2, the trapping centre of light energy is
A. P-700
B. P-680
C. Carotene
D. Xanthophyll

Answer 1

Hint:Sunlight is the main source of energy to the plant. They trap it inside the leaves to make their food and energy. Plants have photosystems which occur in a cascade to produce enough energy. There are various pigments in each photosystem that will help in the sunlight capturation.

Complete answer:
 What is photosynthesis? The process by which the plant makes its food is photosynthesis. The process of photosynthesis is carried out in two stages- light reaction and dark reaction.
There are two photosystems in the light reaction-PS1 and PS2. Let us study which forms the trapping centre of light energy.

>Option A. P-700: In the light reaction, P700 is the reaction centre. It is the light-trapping pigment in PS 1(pigment system 1). They are the chlorophyll molecules found in the reaction centre of the photosystem.
>Option B. P-680: In the pigment system2 (PS2), the chlorophyll pigment which captures the sunlight is the P-680. It is found in the core of the photosystem.
>Option C. Carotene: These are the pigments responsible for the colour of many fruits. They are found in the chloroplasts found in the plastids. Plastids synthesize them and store carotenoids. They give yellow, orange, red colours.
>Option D. Xanthophyll: They are the yellow pigments that occur in nature and are a form of carotenoid.
They are found in young leaves and etiolated leaves. They form the accessory pigments of the leaf which absorb the wavelength that chlorophyll cannot. They play an important role in the protection from the excess of sunlight.

Hence the correct the answer is option B: P- 680.

Note: Photosystems occur in the thylakoid membrane of the chloroplast. It can harvest the sunlight and convert it into chemical energy. Photosystem 2 is first in the cascade followed by the photosystem 1. It captures photons and uses this energy to extract electrons from water. These electrons will flow through the cascade and transport the hydrogen ions across the membrane providing power for ATP synthesis.