What is photosynthesis?
Photosynthesis is a chemical process through which plants, some bacteria and algae, produce glucose and oxygen from carbon dioxide and water, using only light as a source of energy.
This process is extremely important for life on earth as it provides the oxygen that all other life depends on.
What does the plant need glucose (food) for?
Just like humans and other living things, plants also need this food for many things. Let's see a few:
Glucose resulting from photosynthesis is used during respiration to release energy that the plant needs for other life processes.
The plant cells also convert some of the glucose into starch for storage. This can then be used when the plant needs them. This is why dead plants are used as biomass, because they have stored chemical energy in them)
Glucose is also needed to make other chemicals such as proteins, fats and plant sugars that are all needed for the plant to carry out essential growth and other life processes.