PLEASE GIVE THE EXACT DEFINITION OF BIOSYNTHETIC PHASE???
The phase in which synthesis of organic substances take place is called biosynthetic phase.
Products of light reaction: ATP, NADPH, CO2 and H2O. The next phase of photosynthesis after light reaction is the biosynthetic phase. In this, ATP and NADPH are used for synthesizing the food.
CO2 is fixed to form CO2 fixation product.This stage is also called the dark phase as it is independent of light, but deals with the products of light reaction. The reaction involved in the biosynthetic phase takes place in the stroma of chloroplasts.
- In some plants, the first product of CO2 fixation is a 3-carbon compound called 3-phosphoglyceric acid (PGA). These plants are said to adopt the C3 pathway.
In other plants, the first CO2 fixation product is a 4-carbon compound called oxaloacetic acid. These plants are said to adopt the C4 pathway.
Light reactions or the photochemical phase include light absorption, water splitting, oxygen release, and the formation of high-energy chemical intermediates, ATP and NADPH. Products of light reaction are ATP, NADPH and O2. Of these O2 diffuses out of the chloroplast while ATP and NADPH are used to drive the processes leading to the synthesis of food, more accurately, sugars. This is the biosynthetic phase of photosynthesis.