Question

Name the process by which leaves can prepare their food.

Answer 1

Hint: The process is an anabolic and endergonic process which also purifies air as plants give out oxygen while performing this and absorb the carbon dioxide. It is the single most physio-biochemical process of the world on which the existence of life on earth depends upon.

Complete answer:
The process by which the leaves prepare their food is photosynthesis. Photosynthesis can be defined as the synthesis of carbohydrates or food from sunlight, water and carbon dioxide by the green plants.
The leaves of the plants are the site of the photosynthesis as they have chloroplast which is the green-colored plastids and the site for photosynthesis. These are semi-autonomous organelles that are well distributed in the cytoplasm of the plant cells.
Within the chloroplast, a membranous system consisting of grana, the stroma, lamellae and fluid stroma is present. This system is responsible for trapping light energy and synthesis of ATP and NADPH during photosynthesis.
These chloroplasts contain the main photosynthetic pigments i.e. chlorophyll. Carotenoids, anthocyanins, and xanthophyll are other accessory photosynthetic pigments present in the plant cells.
There are seven types of chlorophyll pigments. Chlorophyll is the green colored pigment of the plants as it cannot absorb green light. The chlorophyll molecules are made up of a tetrapyrrole ring known as head and a phytol alcohol tail.
Besides plants some bacteria and cyanobacteria also show photosynthesis. Bacteria show anoxygenic photosynthesis as they do not use water and do not evolve oxygen. Cyanobacteria were the first organisms to evolve oxygen during photosynthesis and show oxygenic photosynthesis.

Note: Plants are autotrophic in nature i.e. they synthesize their own food by trapping solar energy and converting it into chemical energy. All other living organisms are directly or indirectly dependent upon plants for food.