Chapter g Electron transport and oxidative phosphorylation
Chapter 9 Electron transport and oxidative phosphorylation
第一节Ou| ine of bio- oxidation 切生命活动都需要能量。 所有生物都可以看成是能量的转换者。 这种能量的流动驱动着生命的维持与繁衍
一切生命活动都需要能量。 所有生物都可以看成是能量的转换者。 这种能量的流动驱动着生命的维持与繁衍。 第一节 Outline of Bio-oxidation
Some historical facts about our understanding on oxidative phosphorylation 1930s: Pyruvate was known to be completely oxidized to co2 via the citric acid cycle(with O2 consumed) 1930s: NAD+ and Fad were found to be e carriers between metabolites and the respiratory chain 1930s: Role of atp and general importance of phosphorylation in bioenergetics were realized
Some historical facts about our understanding on oxidative phosphorylation • 1930s: Pyruvate was known to be completely oxidized to CO2 via the citric acid cycle (with O2 consumed). • 1930s: NAD+ and FAD were found to be ecarriers between metabolites and the respiratory chain. • 1930s: Role of ATP and general importance of phosphorylation in bioenergetics were realized
1950s: Isolated mitochondria were found to effect the obligatory coupling of the phosphorylation of adp and the e- transfer from NADH to O2 1961, the chemiosmotic hypothesis was proposed for linking the e- transfer and ADP phosphorylation(based on the uncoupling phenomenon and the intactness requirement) 1960s, ATP synthase was identified from mitochondria
• 1950s: Isolated mitochondria were found to effect the obligatory coupling of the phosphorylation of ADP and the e- transfer from NADH to O2 . • 1961, the chemiosmotic hypothesis was proposed for linking the e- transfer and ADP phosphorylation (based on the uncoupling phenomenon and the intactness requirement) • 1960s, ATP synthase was identified from mitochondria
The Overall picture of oxidative phosphory lation.It occurs on the of Intermembrane mitochondria or the plasma space membrane of bacteria) mitochondna 1930s Transporter Citric acid cy (glycolysis) OO HSC。A P+ GDP GTP 1930s Pyruvate CHa-C-C-OH SCOA 2C2 Acetyl CoA 3NAD3NADH FAD ATP+ AM HSCOA →FADH2 HSCOA/ PP 7 Fatty acyl atty acyl FAD Mitochondrial Transporter NADH Shuttle NADH NAD+ 1940s-1950s ATP ADP ADP complex FADH2 P 2e+H H2o NADH NAD NAD FAD H 1960s Oxidative phosphorylation Electron Electron transport via the transport complexes respiratory chain Transport of metabolites Pyruvate dehydrogenase and citric acid cycle into the mitochondrion ATP synthesis by FoF Fatty acid metabolism using proton-motive force Electron transport from NADH and FADH. to ATP export, ADP and P, import oxygen; generation of proton-motive force
The Overall picture of oxidative phosphorylation It occurs on the cristae of mitochondria or the plasma membrane of bacteria) 1930s 1960s 1930s (glycolysis) 1940s-1950s Electron transport via the respiratory chain Oxidative phosphorylation
1. overview: site, mitochondrion Outer membrane Inner membrane Intermembrane space Matrix Cristae An electron micrograph of mitochondrion
1. overview: site, mitochondrion An electron micrograph of mitochondrion
2. features of biological oxidation 与非生物氧化相比 (1)共同点: 叱化学本质相同,都是失电子反应,如脱氢、加氧、 传出电子 同种物质不论以何种方式氧化,所释放的能量相同
2. features of biological oxidation 与非生物氧化相比 (1) 共同点： 化学本质相同，都是失电子反应，如脱氢、加氧、 传出电子 同种物质不论以何种方式氧化，所释放的能量相同
2. features of biological oxidation (2)不同点:与非生物氧化相比 生物氧化是酶促反应,反应条件(如温度、pH) 温和;而体外燃烧则是剧烈的游离基反应,要求 在高温、高压以及干燥的条件下进行。 ·生物氧化分阶段逐步绶慢地氧化,能量也逐步 释放;而体外燃烧能量是爆发式释放出来的 生物氧化释放的能量有相当多的转换成ATP中活 跃的化学能,用于各种生命活动; 体外燃烧产生的能量则转换为光和热,散失在环 境中
（2）不同点： 与非生物氧化相比 生物氧化是酶促反应，反应条件（如温度、pH） 温和；而体外燃烧则是剧烈的游离基反应，要求 在高温、高压以及干燥的条件下进行。 生物氧化分阶段逐步缓慢地氧化，能量也逐步 释放；而体外燃烧能量是爆发式释放出来的。 生物氧化释放的能量有相当多的转换成ATP中活 跃的化学能，用于各种生命活动； 体外燃烧产生的能量则转换为光和热，散失在环 境中。 2. features of biological oxidation
3. production of CO2 and H2O 1、CO的生成 直接脱羧:丙酮酸脱羧酶、酪氨酸脱羧酶 氧化脱羧:丙酮酸脱氢酶复合物 2、水的生成 主要是在包括脱氢酶、传递体和氧化酶组成 的生物氧化体系催化下生成的
1、CO2的生成 直接脱羧：丙酮酸脱羧酶、酪氨酸脱羧酶 氧化脱羧：丙酮酸脱氢酶复合物 2、水的生成 主要是在包括脱氢酶、传递体和氧化酶组成 的生物氧化体系催化下生成的。 3.production of CO2 and H2O
4. high-energy substance 定义 高能化合物: 在标准条件下(pH7,25℃,1mo/八L)发生水解时,可 释放出大量自由能的化合物。习惯上把“大量”定义为 5kca/mo(即20.92kJ/mo)以上 高能磷酸化合物: 分子中含磷酸基团,它被水解下来时释放出大量的自 由能,这类高能化合物。 高能键: 在高能化合物分子中,被水解断裂时释放出大量自 由能的活泼共价键。高能键常用符号“~”表示
4. high-energy substance 高能化合物： 在标准条件下(pH7，25℃，1mol/L)发生水解时，可 释放出大量自由能的化合物。习惯上把“大量”定义为 5kcal/mol(即20.92kJ/mol)以上。 高能磷酸化合物： 分子中含磷酸基团，它被水解下来时释放出大量的自 由能，这类高能化合物。 高能键： 在高能化合物分子中，被水解断裂时释放出大量自 由能的活泼共价键。 高能键常用符号“ ~ ”表示。 定义