Reading background information because it gives ideas from the author himself.
The answer is D, for when one tropic level is eaten by the tropic level above it, the tropic level is supporting the higher one. I. E. Rabbits are supported by the grass because rabbits eat the grass. Also, the grass population would be larger than rabbits, the rabbits larger than snakes, so on and so forth, so B is ruled out. B states that each population is larger than the one BEFORE it, but there is no way there would be more rabbits than grass. Also, there are both herbivores and carnivores in the food chain, so A and C are out. The best answer is D.
It will be transported into the cell through the process of endocytosis, which is a form of active transport. Active transport requires energy in the form of ATP. Hope this helps! :)
Animals use the respiratory system to breathe in oxygen and other gases and expel gases like CO2, right? O2 in, CO2 out.
Answer:
Citrate Synthase facilitates the formation of citrate by deprotonating Acetyl CoA and by protonating the carbonyl oxygen of oxaloacetate
Explanation:
Citrate synthase is a key enzyme in the citric acid cycle that functions to catalyze the formation of citrate from oxaloacetate and acetyl-CoA: acetyl-CoA + oxaloacetate + H2O >> citrate + CoA-SH (Coenzyme A ). This enzyme contains three amino acids at its active site that work together to catalyze the conversion of acetyl-CoA and oxaloacetate into citrate. This active site acts by abstracting (deprotonating) a proton from the alpha carbon of Acetyl CoA which serves as the nucleophile. Subsequently, the active site of the enzyme also protonates the carbonyl oxygen of oxaloacetate, which then suffers nucleophilic attack and thereby facilitating nucleophilic substitution reaction.
