Question

Which organelles are involved in photorespiration?
A. Chloroplast, peroxisomes, and mitochondria.
B. Lysosomes, peroxisomes, and mitochondria.
C. Golgi apparatus, Lysosomes, and peroxisomes.
D. Golgi apparatus, mitochondria, and ribosomes.

Answer 1

Hint: This side reaction starts a pathway called photorespiration, which ultimately results in loss of already-fixed carbon as \[C{{O}_{2}}\] rather than fixing carbon. Photorespiration is a method that involves the loss of fixed carbon in the presence of light in plants as \[C{{O}_{2}}\]. In chloroplasts, it is started. ATP or NADPH is not created by this method and is a wasteful process

Complete answer: Three cellular organelles involved in photorespiration are the chloroplast, peroxisome, and mitochondria.
Diverse photorespiratory pathway steps are as follows:
(a) RuBP carboxylase acts as oxygenase in the presence of high \[{{O}_{2}}\] and results in the formation of 3PGA (phosphoglyceric acid) and 2-phosphoglycolate, 2-phosphoglycolate loses the glycolate-making PO4 party.
(b) Synthesized glycolate enters into peroxisomes in the chloroplast.
(c)The oxidase enzyme oxidizes glycolate into glyoxylate and \[{{H}_{2}}{{0}_{2}}\].
(d) Glyoxylate is converted by glutamate glyoxylate transaminase (enzyme) into glycine (amino acid).
(e) Two glycine molecules form a serine and one molecule \[C{{O}_{2}}\] but no ATP and NADPH are produced in mitochondria.
(f) Lastly, serine reaches the mitochondria and is converted into carbohydrates (3 carbons) and phosphoglycolate (2 carbons).
(g)Phosphoglycolate can soon form glycolate. Glycolate soon transforms into glycine and glycine into serine and \[C{{O}_{2}}\] in peroxisomes, without developing assimilatory forces ATP and NADPH.
Rubisco is an enzyme used by the Calvin cycle for the fixation of carbon dioxide. The high oxygen concentration inhibits the Calvin cycle and helps rubisco to oxygenate and contributes to the production of 2-phosphoglycolic acid, which is metabolized into PGA by the photorespiration mechanism that enters the Calvin cycle further. The photorespiration process occurs in three major organelles in sequential stages. There are chloroplasts, mitochondria, and peroxisomes.
So, choice A- Chloroplast, peroxisomes, and mitochondria is the correct answer.

Note: Photorespiration does not exist in \[{{C}_{4}}\] plants. This is because these plants have a function at the enzyme site that raises the \[C{{O}_{2}}\] concentration. Photorespiration expends energy and reduces the production of sugar, so when rubisco tries to start this route, a significant molecular faux pas is committed.