Question

Observe the labeled and write down the following :

1. Which gas is passed out into the atmosphere at A?

2. What raw material required for photosynthesis, enters the leaf at B? 

3. Describe the major steps involved at C in the synthesis of sugar.

Answer 1

1. O₂ 

2. H₂O 

3. CO₂ is reduced to sugar (glucose or fructose), by the biochemical reaction of photosynthesis (Calvin cycle). 

It has 3 major steps

• Carboxylation – During which CO₂ combines with RuBP. 
• Reduction – During which carbohydrate is formed at the expense of the photochemically made ATP and NADPH.
• Regeneration – During which is the CO₂ acceptor (RuBP) is formed again so that the cycle continues.