What happens when RuBisCO binds to oxygen?
In proteins that bind oxygen, like myoglobin, carbon dioxide is easily excluded because carbon dioxide is slightly larger. But in rubisco, an oxygen molecule can bind comfortably in the site designed to bind to carbon dioxide. Rubisco then attaches the oxygen to the sugar chain, forming a faulty oxygenated product.
Does oxygen bind to RuBisCO in photorespiration?
Rubisco can bind to either carbon dioxide or oxygen depending on environmental conditions.
How does photorespiration occur?
Photorespiration generally occurs on hot, dry, sunny days causing plants to close their stomata and the oxygen (O2) concentration in the leaf to be higher than the carbon dioxide (CO2) concentration.
What happens when RuBP combines with oxygen?
(b) In photorespiration, oxygen gas combines with RuBP to form an unstable molecule that breaks down into glyceraldehyde phosphate and glycolic acid, a two-carbon molecule that is further catabolized into carbon dioxide.
When can photorespiration occur in plants?
Photorespiration happens in C3 plants when the CO2 concentration drops to about 50 ppm. The key enzyme that accomplishes the fixing of carbon is rubisco, and at low concentrations of CO2 it begins to fix oxygen instead.
Does photorespiration need oxygen?
The reaction of RUBISCO with oxygen and metabolic processing of the resulting 2-PG is called “photorespiration”. It is called this because it only occurs in the light (mitochondrial respiration continues in darkness) and because it consumes oxygen and produces carbon dioxide, just like mitochondrial respiration.
How does function of RuBisCO enzyme affected by concentration of O2 and CO2?
Answer: RuBisCO has a much greater affinity for CO2 than for O2. It is the relative concentration of O2 and CO2 that determines which of the two will bind to the enzyme. In plants some O2 does bind to RuBisCO and hence, CO2 fixation is- decreased.
Does RuBisCO involve in respiration?
What is the role of RuBisCO?
Ribulose 1,5-bisphosphate carboxylase/oxygenase (RubisCO) catalyzes the assimilation of atmospheric CO(2) into organic matter and is thus central to the existence of life on earth.
Which of the following does photorespiration occur?
Photorespiration is a wasteful process, which occurs in C3 plants. It happens due to oxygenase activity of RuBisCO. Due to oxygenase activity of RuBisCO, oxygen rather than carbon dioxide is fixed in the first reaction of Calvin cycle.