Question

What is the first stable intermediate product of photosynthesis?
a) Glucose
b) Formaldehyde
c) Phosphoglyceric acid
d) PGAL

Answer 1

Hint : It is a biochemically significant metabolic intermediate in both glycolysis and the Calvin cycle.

Complete answer : Photosynthesis is the process through which green plants and other organisms transform light energy into chemical energy. During the process of photosynthesis, the light energy which is captured is used to convert water, carbon dioxide and minerals into oxygen and other Rich organic compounds. In terms of a chemical process, Photosynthesis is the oxidation-reduction reaction process (Oxidation means the removal of electrons and Reduction means a gain of electrons). Carbohydrates and sugar sucrose are the major organic product of photosynthesis. The first stable intermediate product of photosynthesis is Phosphoglyceric acid. Phosphoglyceric acid is the 3 carbon compound called 3- Phosphoglycerate which contains sugar phosphates, Amino acids, Sucrose and carboxylic acids. When photosynthesis was stopped after 2 seconds, the principal radioactive product was Phosphoglyceric acid, which was identified as the first stable compound formed during carbon dioxide fixation in green plants.

Additional information.
Here, we discuss Calvin Cycle, the main function of this cycle is to create three-carbon sugars and the first stable compound was found by the help of this cycle i.e. Phosphoglyceric acid(PGA) and this can be used to build other sugar compounds such as glucose, starch and cellulose. So, this makes the Calvin cycle important for the existence of most ecosystems.

Thus, the correct answer is C i.e. Phosphoglyceric acid.

Note : The factors that affect the rate of photosynthesis are amount of light, carbon dioxide, temperature, water and availability of minerals.