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A Handbook of Biology
3. ËXPËRÏMËÑTS BÝ JÜLÏÜS VØÑ SÅÇHS (1854)
He proved that-
Glucose is produced when plants grow and it is usually stored
as starch.
Chlorophyll is located in special bodies (chloroplasts).
Glucose is made in the green parts of plants.
4. ËXPËRÏMËÑTS BÝ T.W ËÑGËLMÅÑÑ (1843 - 1909)
He split the light using a prism into its spectral components and
illuminated a green alga (Cladophora) placed in a suspension
of aerobic bacteria.
(Odisha NEET 2019)
The bacteria were used to detect the sites of O2 evolution.
He observed that the bacteria accumulated mainly in the
region of blue and red light of the split spectrum. (NEET 2019)
It was the first described action spectrum of photosynthesis. It
resembles the absorption spectra of chlorophyll a & b.
By the middle of 19th century, it was discovered that plants use
light energy to make carbohydrates from CO2 & H2O.
Empirical equation of the process of photosynthesisis
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Light
2
2
2
2
CO +H O
[CH O]+O
Where, [CH2O] represents a carbohydrate (e.g., glucose).
5. ËXPËRÏMËÑTS BÝ ÇØRÑËLÏÜS VÅÑ ÑÏËL (1897-1985)
Cornelius van Niel (microbiologist) conducted some studies in purple
and green sulphur bacteria.
He demonstrated that photosynthesis is a light-dependent reaction in
which hydrogen from a suitable oxidisable compound reduces CO2 to
carbohydrates.
This can be expressed by:
Light
2
2
2
2
2H A+CO
2A+CH O+H O
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