Photosynthesis is the process that produces food energy for most life forms. Photosynthesis is the synthesis reaction that plants perform to produce glucose a source of energy. Photosynthesis uses light energy and carbondioxide (CO2) molecules and water (H2O)molecules to create glucose (C6H12O6) and the waste gas oxygen (O2).

All life on earth depends directly or indirectly on photosynthesis. It provides food either directly or indirectly for most living things. Converts light energy into chemical energy which is stored in the form of organic matter, usually the carbohydrates and along with the release of O2 form end products of photosynthesis.

Some of the solved problems based on photosynthesis is given below:

Problem 1: Describe the overall reaction of photosynthesis process.

Older scientist were of the opinion that CO2 was reduced to the level of carbohydrates by various enzymatic actions. So the equation is 

CO2 + H2O $\rightarrow$ Organic matter + O2

By tracer techniques with the help of isotopes the whole equation is given as

CO2 + 2H2O $\rightarrow$ CH2O + H2O + O2

The overall new reaction for photosynthesis according to Ruben and Kamen (1941) is given below.

6CO2 + 12H2O $\xrightarrow[Light \ energy]{Chlorophyll}$ C6H12O6 + 6O2 + 6H2O

Problem 2: Which wavelength of solar energy are used in photosynthesis by a green plant?

Photosynthesis in green plants uses solar energy of intermediate wavelengths (400 - 700 nm) known as light. Most effective are violet, blue, orange and red light; least effective is green light. Each chloroplast has several kinds of pigments, with each kind absorbing best at wavelengths different from others.