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.
True. If (environmental) conditions were bad, the seed would not be able to survive :)
Answer:
Darwin's theory consisted of two main points; 1) diverse groups of animals evolve from one or a few common ancestors; 2) the mechanism by which this evolution takes place is natural selection. This SparkNote will first take a look at Origin of the Species, and then more closely examine Darwin's theories.
From cells to tissues to organs to organ systems to the organism itself. That is the hierarchy of cytology to most eukaryotic organisms. Cell is the basic unit of every living organism. This basic unit has specialization that functions differently for each pattern of structural and functional processes.
