Answer:
There is no regulatory protein that oxidizes these Calvin cycle enzymes; oxidation is spontaneous.
Explanation:
Four enzymes of the Calvin cycle are regulated by sunlight. These enzymes are namely Ribulose 5-phosphate kinase, fructose 1,6-bisphosphatase, sedoheptulose 1,7-bisphosphatase, and glyceraldehyde 3-phosphate dehydrogenase.
The inactive form of these enzymes has disulfide bonds between two Cys residues. In the presence of sunlight, the reduced thioredoxin that obtains electrons from PS-I via ferredoxin reduces the disulfide bonds between the Cys residues of these enzymes.
The reduction of the bonds brings about the confirmation changes to make the enzyme active.
At nightfall, these bonds are spontaneously re-oxidized and there is no reduced thioredoxin available to reduce them again. The spontaneous oxidation of the disulfide bonds of these enzymes at nightfall makes them inactive again.
It is only one...................
Answer:
Modern method of irrigation is Sprinkling, Subirrigation,intrasoil and salt leaching are the principal purposes of surface irrigation
