TCA背景知识
2、细胞呼吸（cell respiration） 要经历三个阶段：糖酵解阶 段、柠檬酸循环阶段、氧化 磷酸化阶段。 3、糖酵解的产物丙酮酸进入 TCA之前有一准备过程，即 形成乙酰CoA。
TCA准备阶段
丙酮酸在丙酮酸脱氢酶系催化下氧化脱羧形 成乙酰辅酶A。
IRREVERSIBLE
• In 1937, Krebs found that citrate could be formed in muscle suspensions if oxaloacetate and either pyruvate or acetate were added. Now, he get a cycle:
• In 1932, Krebs was studying the rates of oxidation of small organic acids by kidney and liver tissue. Only a few of substances were active in these experiments---notably succinate, fumarate, acetate, malate, and citrate.
Brief history of TCA
• The first major investigation into the intermediary metabolism of oxidation was that of Thunberg, who examined systematically the oxidizability of organic substances in isolated animal tissues. Between 1906 and 1920 he tested the oxidation of over 60 organic substances, chiefly in muscle tissue. He discovered the rapid oxidation of the salts of a number of acids, such as lactate(乳酸盐), succinate(琥珀酸盐), fumarate(延胡索酸盐), malate(苹果酸盐), citrate(柠檬酸盐), and glutamate(谷氨酸盐).
