Early Experiment for Photosynthesis :- NEET/AIIMS/JIPMER

Photosynthesis is a term used to describe the process of preparation of food by green plants. The process uses energy from sunlight to convert carbon dioxide and water into the molecules which are needed for plant’s growth and development. The green pigment in plants is responsible for absorbing light energy and converting into food. The process is a very important one as it releases oxygen into the atmosphere and is a primary source of food. 

Early Experiment for Photosynthesis:

Scientist Joseph Priestly performed various experiments in the year of 1770 which showed the role of air in the growth of green plants.

• The first experiment was carried out using a candle, mice, jar and a plant. When he placed a candle and mice in a jar, candle extinguished and mice fainted after sometime as shown in gif a and b. He then placed a plant in the jar along with mice and candle. Mouse stayed alive and the candle was also burning which brought priestly to the hypothesis that “plants restore the air whatever breathing animals and burning candles remove.
•  Another experiment he performed involve a similar set of plants. He showed that small bubbles are formed around the green parts of the plants in sunlight whereas there are no bubbles formed during the night. From this experiment, he concluded that those bubbles formed were oxygen molecules.
• Another scientist named Julius von Sachs performed an experiment in the year 1854 and showed that glucose is produced during the growth of plants. Glucose is made in chlorophyll and is stored in the form of starch.

• These green pigments (chlorophyll) are stored in specialized plant cells. There were some more scientists who worked in a similar field and described the entire process of photosynthesis by chemical equations.

• T.W Engelmann carried out an experiment using prism which split the light into several components and illuminated green algae (cladophora) which was placed in the suspension of aerobic bacteria.

• Using these bacteria, he detected the site of oxygen evolution. Most of the bacteria were accumulated in the red and blue light area. In the 19^th century, the empirical equation which represented the process of photosynthesis was:

• Another Scientist Cornelius van Neil added that the process of photosynthesis is a light dependent reaction and the equation represented as-
• He even concluded that oxygen evolved from the green plants comes from hydrogen and water. The final equation which represents photosynthesis is

• Another Scientist Cornelius van Neil added that the process of photosynthesis is a light dependent reaction and the equation represented as-

• He even concluded that oxygen evolved from the green plants comes from hydrogen and water. The final equation which represents photosynthesis is-

Where C₆H₁₂O₆  is glucose.