Photosynthesis Notes:-

 

Chapter:-Photosynthesis

Q.1: Define photosynthesis and add a note on its significance:   

1)   Definition: Photosynthesis is intracellular anabolic process in which low molecular weight substance like CO2 and water combine together in the presence of light and chlorophyll to produce high molecular weight compounds like glucose (stored food/chemical energy) along with oxygen and water as by products.

6CO2 + 12H2O----------C6H12O6 +60₂+ 6H2O

                                        Glucose

2)  Significance of photosynthesis:

A) Trapping of solar energy: Solar energy is trapped by chlorophyll pigments and is converted into chemical energy.

B) Stored Food: -

Food synthesized in the form of glucose which used by all living organisms (heterotrophs) through food chain.

C) Evolution of oxygen: Oxygen is released during the process of photosynthesis which is used by living organisms for respiration.

D) CO -2O2 balance: CO2 is the raw material for photosynthesis and oxygen is by-product. Number of CO2 molecules used and oxygen released is same.

E) Ozone layer: Molecular oxygen released during the process of photosynthesis is used to synthesize ozone which protects us from ultraviolet radiations of sun.

F) Raw materials for various industries are obtained from plants.

G) Fossil fuels like coal, natural gas, petrol etc. are photosynthetic products of extinct plants.