Photosynthesis early experiments

Introduction

Photosynthesis is the process through which plants make the food they need to survive. In this process, light energy is absorbed by the plants and turned into chemical energy, which in turn is used to produce oxygen as a result of photosynthesis. The plants have been following this method for a very long time. However, it was not until 1800 that photosynthesis was discovered and identified, and multiple scientists carried out a variety of tests to verify the existence of photosynthesis in various forms.

The Discovery of Photosynthesis – The Early Experiments

Photosynthesis necessitates the use of basic elements such as water and carbon dioxide, as well as cellular components such as plastids. Plants can only synthesis carbohydrates when they are exposed to light, which means that they must use these raw materials. These fundamental characteristics of photosynthesis were discovered in the mid-nineteenth century.

Experiment done to Prove the Relevance of Carbon Dioxide in Photosynthesis

Requirement of Materials: A healthy plant, a wide-mouthed glass bottle with a split cork, potassium hydroxide solution (KOH), and starch solution are all that are required. 

Experiment:

1. Take a healthy potted plant and place it in a darkroom for two to three days to ensure that the leaves are free of starch.
2. Pour 10-15 mL of potassium hydroxide solution into a wide-mouthed glass bottle and split the cork vertically.
3. Carefully place half of a leaf into a glass bottle through the split cork, leaving the other half exposed to the air. 4.
4. Leave the entire unit in direct sunshine for around 3 – 4 hours, undisturbed.
5. Remove the leaf from the plant after 4 hours and carefully remove it from the bottle, allowing it to soak in the starch solution for a few minutes.
6. We can see that the half of the leaf that was within the glass bottle (containing the KOH solution) did not show any colour change, however the other half of the leaf that was exposed to the environment turned dark brown, showing the presence of starch in the leaf.

Conclusion: Based on the results of this experiment, we can deduce that carbon dioxide is required for photosynthesis. Each leaf component received equal amounts of water, chloroplasts, and sunlight; however, only half of it was exposed to carbon dioxide because it was enclosed in a glass bottle half of it was exposed to carbon dioxide

In later years, scientists conducted a large number of impromptu experiments in order to better understand the components of photosynthesis. Joseph Priestley (1733-1804) was the first scientist to carry out these experiments, while others followed in his footsteps.

Joseph Priestley conducted an experiment.

After conducting a series of experiments in 1770, Joseph Priestley came to the conclusion that air is necessary for photosynthesis as well as for the development of plants.

Requirement of Materials: A candle, rat, a bell jar, and a plant.

Experiment:

1. First and foremost, a burning candle and a mouse were kept together in a single bell jar for safety reasons.
2. Eventually, the flame was out and the rat succumbed to his injuries.
3. For the second time, he placed a burning candle, a rat, and a green plant in a bell jar together with a green plant.
4. He noticed that neither the candle nor the rat was extinguished.

As a result of his observations, the scientist Priestley came to the conclusion that the air in the bell jar was contaminated in the first example because of a candle burning in it and the presence of a mouse. However, in the second instance, the plant was able to restore the air quality that had been harmed by the candle and the rat. Scientists, on the other hand, did not discover this function of the plants until much later.

Various Other Experiments

Similarly, scientist Jan Ingenhousz did tests utilising the identical set-up, with the difference being that the presence of sunshine was highlighted as being a vital product for plants in order to refresh contaminated air that had been polluted by either the candle or the rat, respectively.

During his research, Jean Senebier came to the conclusion that plants consume carbon dioxide and release oxygen during the photosynthesis process.

Plants transform light energy into chemical energy, according to Julius Robert Mayer discover in the 1800s.

Later, Julius von Sachs discovered that plants were capable of producing glucose.

T.W. Engelmann established the role of chlorophylls in plants, and Cornelius van Niel found that plants release oxygen from water (H2O), not carbon dioxide, during the photosynthesis process. He also provided the equation for photosynthesis in general.

Scientists drew a diagram of the photosynthesis process to help them understand it better. They came to the conclusion that light is required for photosynthesis, and that plants employ carbon dioxide and water to manufacture glucose (carbohydrate), where water molecules serve as hydrogen donors and oxygen (O2) is produced as a by-product of this biological process.

Conclusion

Photosynthesis is the process through which green plants convert water, carbon dioxide, and chlorophyll molecules into glucose molecules for use in their metabolism. In order to demonstrate the role of light and carbon dioxide in the synthesis of food in plants, a number of experiments were carried out by various scientists. Physicists such as Priestley and Ingenhousz demonstrated that plants emit pure oxygen (oxygen) when exposed to light, which is then taken up by other creatures for the purpose of respiration. Engermann conducted a number of studies later on, in order to determine the action spectrum of light, and discovered that the greatest amount of photosynthesis takes place in the blue and red portions of the visible spectrum.