What does RuBP react with in Photorespiration?
The first step of photorespiration is oxygenation. It is catalyzed by RUBISCO and converts RUBP to one molecule fo 3PGA and one molecule of 2PG, which is a 2 carbon compound with one phosphate group. The oxygenation reaction is influenced by environmental factors.
What causes Photorespiration to occur?
Photorespiration is a wasteful pathway that occurs when the Calvin cycle enzyme rubisco acts on oxygen rather than carbon dioxide.
How is rubisco involved in Photorespiration?
Photorespiration (also known as the oxidative photosynthetic carbon cycle, or C2 photosynthesis) refers to a process in plant metabolism where the enzyme RuBisCO oxygenates RuBP, wasting some of the energy produced by photosynthesis. Photorespiration also incurs a direct cost of one ATP and one NAD(P)H.
What is formed when RuBP reacts with O2?
Answer: There are two products that are formed when RUBP combines with O2 they are 3-PGA and phosphoglycolate. RuBP oxygenase-carboxylase (rubisco) enzyme that is responsible for the reaction.
Which occurs during the Calvin cycle and also during photorespiration?
In the Calvin cycle, 6 CO2 molecules combine with 6 RuBP acceptors, making 12 3-PGA molecules. These are converted into 12 G3P sugars. In the photorespiration pathway, 6 O2 molecules combine with 6 RuBP acceptors, making 6 3-PGA molecules and 6 phosphoglycolate molecules.
What molecule is released during photorespiration?
Photorespiration is the process of light-dependent uptake of molecular oxygen (O2) concomitant with release of carbon dioxide (CO2) from organic compounds. The gas exchange resembles respiration and is the reverse of photosynthesis where CO2 is fixed and O2 released.
What molecule is released during Photorespiration?
Photorespiration wastes energy and steals carbon Two molecules are produced: a three-carbon compound, 3-PGA, and a two-carbon compound, phosphoglycolate.
What is the role of the RuBP carboxylase enzyme in photosynthesis?
function in photosynthesis The enzyme ribulose 1,5-bisphosphate carboxylase/oxygenase (Rubisco) catalyzes the formation of organic molecules from CO2. As the major enzyme of all photosynthetic cells, Rubisco is the most abundant protein on Earth.
Which enzyme is responsible for photorespiration?
bisphosphate-carboxylase/oxygenase (RUBISCO)
Photorespiration is initiated by the oxygenase activity of ribulose-1,5-bisphosphate-carboxylase/oxygenase (RUBISCO), the same enzyme that is also responsible for CO2 fixation in almost all photosynthetic organisms.
What are the two molecules formed when RuBP combines with oxygen during Photorespiration?
During photorespiration, when two O2 molecules react with 2 moles of RUBP then how many 3 – PGA molecules are form from 2 molecules of 2 phosphoglycolate A 2 CORRECT ANSWER SOLUTION During photorespiration, 2 molecules of RuBP reacts with two molecules oxygen moelcules and form into 2 molecules of Phosphoglycolic acid( …
What is Calvin cycle RuBP?
Carbon dioxide enters the cycle and is fixed by Rubisco to a 5-carbon sugar called ribulose biphosphate (RuBP), which is immediately broken down to form two 3-carbon molecules of phosphoglycerate (PGA).
Why is the process whereby O2 is added to RuBP called photorespiration?
Under what conditions does it occur and why? Photorespiration is when the enzyme Rubisco fixes oxygen instead of carbon dioxide and adds oxygen to RuBP instead of carbon dioxide. Photorespiration is inefficient because it gives off CO2 instead of fixing it, it does not produce any sugars and it wastes ATP and NADPH.