Question

The role of chlorophyll in photosynthesis is
(a) Absorption of $CO_2$
(b) Absorption of light
(c) Absorption of light and photochemical decomposition of water
(d) Absorption of water

Answer 1

Chlorophyll is an important component of the life-sustaining process called photosynthesis. It is the basic pigment which is the basis of the whole process. It is used in both the process of light reaction and dark reaction.

Complete answer:
Chlorophyll is a green-colored pigment. It is a molecule that absorbs the light photons from the sun and uses its energy to create carbohydrates from $CO_2$ and water. Therefore the chlorophyll is used as an energy absorber and helps in the photochemical decomposition of water, which is also called photolysis. These processes in turn provide energy and food to the plants. Humans are directly or indirectly dependent on plants for food and many other resources.

Additional Information:
1. Chlorophyll is found in the thylakoid membrane, the space between the thylakoid and chloroplast membrane is called the stroma.
2. Chloroplast is 2 membraned plant organelle, which are outer and inner membrane with intermediate space in between.
3. Stacks of thylakoids are called grana.
4. Thylakoids contain chlorophyll which is necessary for plants’ photosynthesis.
So, the correct answer is, ‘Absorption of sunlight and photochemical decomposition of water’.

Note: Chloroplasts and mitochondria are similar in many aspects: firstly, they both are double membranes. Secondly, they have their own DNA. Thirdly they both are energy producers, mitochondria produce energy in animal cells and chloroplasts assist in producing energy in plant cells. The inner membrane of mitochondria is folded in the form of cristae and the inner membrane of chloroplasts is modified in the sacs called thylakoids.