Question

Ratio between 2-carbon and 3-carbon intermediate having NH2 group formed in photosynthetic oxidation cycle is
A) 2:1
B) 1:1
C) 3:2
D) 3:4

Answer 1

During photosynthesis, peroxisome molecules are converted into glycine and serine. This cycle is also known as the $C_2$ cycle.

Complete answer:
Oxidative photosynthetic cycle is also known as photorespiration. It refers to a process of plant metabolism where RuBP is originated by RuBisCO enzyme. Some amount of energy is wasted during the process which is produced during photosynthesis.
A network of complex enzymes are involved in reactions between metabolites that occur between mitochondria, peroxisome and chloroplasts. 3-phosphoglycerate produced in this process is a waste process and made at a reduced rate and RuBP carboxylase is produced in high metabolic cost. Carbon produced in photorespiration is re-released as CO at a percentage of 25%. In case of photooxidation cycle peroxisome is converted into 2- molecules of glycine and 1 molecule of serine. The conversion of glycine to serine is the key step in this process. Hydrogen peroxide produced in the peroxisome is a very cost effective process. It is a strong enzyme from which water and oxygen will produce by the reaction of catalase enzyme. In extremely high temperatures, CO and O is discriminated against because enediol intermediate is unstable in chloroplast.

Hence Option ‘A’ 2:1 is the correct answer.

Note: You must go through the detailed process of photosynthesis and the process of photosynthetic oxidation cycle or photorespiration or oxidative photosynthetic cycle. Whole process occurs in the peroxisome where the amount of glycine is two molecules.