Biosynthesis of Carbohydrates

BIOSYNTHESIS OF CARBOHYDRATES

Carbohydrates are the products of photosynthesis, a biological process that converts light energy into chemical energy. The general process of photosynthesis can be described by:

CO₂ + H₂O  --_{(Green plants)}→ Sugars + O₂

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All green plants and certain algae and bacteria have the capacity to synthesize adenosine triphosphate (ATP) and nicotine adenine dinucleotide phosphate (NADPH). These compounds mediate most of the biosynthetic reactions in plants. There are basically two primary lights:

1. Absorption of light by chlorophyll or energy transfer to chlorophyll by other light absorbing pigments leading to production of ATP and NADPH.

2. Photolysis of water to produce oxygen and electrons which are transferred via carrier species and produces ATP and NADPH, two reactive molecules which work as activating and reducing agents.

Blackmann Reaction: In the subsequent ‘dark reaction’, carbon dioxide is reduced to produce four, five, six, and seven carbon sugars. The reactions were firstly given by Blackmann and hence called as Blackmann reaction. It is estimated that about 4000 × 10⁹ tons of CO₂ is fixed annually through the photosynthetic process. The path of carbon in photosynthesis was first given by Calvin is termed as Calvin cycle.

CO₂ + 2 NADPH₂ + 2 ATP → (CH₂O)_n (Carbohydrate) + H₂O + 2 ADP + 2 NADPH