Question

Molecules of RuBP required to produce 20 molecules of serine in photorespiration are

• A. 60
• B. 40
• C. 20
• D. 80

Answer 1

The correct option is B 40

1 mol. of RuBP in the presence of O${}_2$ splits into 1 mol. of 2-phosphoglycolic acid and 1 mol. of 3 PGA.

1 mol. of Phosphoglycolic acid is converted to 1 mol into glycolic acid which oxidized to 1 mol. of glyoxylic acid.

1 mol. of glyoxylic acid by transamination form 1 mol. of glycine.

2 mol. of glycine in peroxisome form 1 mol. of serine.

Therefore, 2 mol. of RuBP require to form 1 mol. of serine so 40 mol. require to form 20 mol. of serine.

Hence, the correct answer is '40'.