Acetyl complementary enzymatic A and acid of careless acyl second are synthesized in citric acid citric acid is formed below enzymatic catalysis, begin circulation of 3 carboxylic acid then.

• 乙酰辅酶a和草酰乙酸在柠檬酸合成酶的催化下形成柠檬酸，遂开始三羧酸循环。