Reaction
ATCase is a highly regulated enzyme that catalyses the first committed step in pyrimidine biosynthesis, the condensation of aspartate and carbamyl phosphate to form N-carbamyl-L-aspartate and inorganic phosphate. ATCase controls the rate of pyrimidine biosynthesis by altering its catalytic velocity in response to cellular levels of both pyrimidines and purines. The end-product of the pyrimidine pathway, CTP, induces a decrease in catalytic velocity, whereas ATP, the end-product of the parallel purine pathway, exerts the opposite effect, stimulating the catalytic activity.
Read more about this topic: Aspartate Carbamoyltransferase
Famous quotes containing the word reaction:
“In a land which is fully settled, most men must accept their local environment or try to change it by political means; only the exceptionally gifted or adventurous can leave to seek his fortune elsewhere. In America, on the other hand, to move on and make a fresh start somewhere else is still the normal reaction to dissatisfaction and failure.”
—W.H. (Wystan Hugh)
“Children, randomly at first, hit upon something sooner or later that is their mother’s and/or father’s Achilles’ heel, a kind of behavior that especially upsets, offends, irritates or embarrasses them. One parent dislikes name-calling, another teasing...another bathroom jokes. For the parents, this behavior my have ties back to their childhood, many have been something not allowed, forbidden, and when it appears in the child, it causes high-voltage reaction in the parent.”
—Ellen Galinsky (20th century)
“In contrast to revenge, which is the natural, automatic reaction to transgression and which, because of the irreversibility of the action process can be expected and even calculated, the act of forgiving can never be predicted; it is the only reaction that acts in an unexpected way and thus retains, though being a reaction, something of the original character of action.”
—Hannah Arendt (1906–1975)