1. Complex I NADH-Q oxidoreductase
   1. proton pump
      1. transmembrane complex (mit. inner membrane)
   2. Dehydrogenase
   3. Step 1: NADH transfer 2e- to FMN
      1. 1st prosthetic group 第一輔酶
      2. FMN -> FMNH2
      3. 黃素蛋白(flavoproteins)
      4. 由核黃素(riboflavin)衍生而來
      5. 常作為輔酶 (coenzyme)
   4. Step 2: FMNH2 transfer 2e- to iron-sulfur clusters
      1. 2nd prosthetic group 第二輔酶
      2. Fe-S clusters 鐵硫團簇(nonheme iron proteins)
      3. Fe3+ -> Fe2+
         1. 1次接收 1 個電子，不需要H+
      4. 4Fe-4S 最常見
   5. Step 3: Fe-S clusters transfer 2e- to coenzyme Q
   6. Step 4: Q take 2H+ from matrix reduced to QH2
2. Complex II Succinate-Q reductase
   1. physical link to TCA cycle
      1. contain succinate dehydrogenase (in TCA 6) to generate FADH2
   2. Internal protein
   3. No H+ Pumping
3. Complex III Q-cytochrome c oxidoreductase
   1. proton pump
      1. transmembrane complex (mit. inner membrane)
   2. 2 types of Cyt C
      1. Cyt b
         1. Heme bL
         2. intermembrane
         3. e-親和力 low
         4. Heme bH
         5. matrix
         6. e-親和力 high
      2. Cyt c1
         1. Heme c1
         2. e-親和力大於 cyt b
      3. Homodimer同質二元體
   3. 2Fe-2S center (Rieske center)
      1. 2Fe-2S + 2Cys + 2His
      2. 高氧化還原電位
         1. His為鹼性aa，在中性環境下帶正電
         2. 易接收電子
   4. step 1
   5. step 2
4. Complex IV Cytochrome c oxidase
   1. proton pump
      1. transmembrane complex (mit. inner membrane)
   2. CuA/CuA
      1. Cu3+ -> Cu2+ 接收 Cyt Cred的電子
   3. Heme a3-CuB
      1. Heme a3 reduce to Fe
      2. CuB reduce to Cu
      3. O2 -> H2O
   4. Cytochrome c oxidase mechanism （搶4 e- pump 4e-)
5. I＋III＋IV -> Respirasome
6. The respiratory chain consists of four complexes
   1. Mass
      1. Subunits
         1. Prosthetic group 輔基
         2. Num. H+ pumping
         3. Transmem. protein (穿膜型)
         4. Oxidant / Reductant
         5. Matrix side (N side)
         6. membrane core
         7. Cytoplasmic side (P side)
   2. Complex I
      1. >900 最大
         1. 46 複雜
            1. Fe-S , FMN
            2. 4
            3. O
            4. NADH
            5. Q
   3. Complex II
      1. 140 最小
         1. 4
            1. Fe-S , FAD
            2. 0
            3. X (嵌膜型)
            4. Succinate
            5. Q
   4. Complex III
      1. 250
         1. 11
            1. Fe-S , Heme b.c
            2. 2
            3. O
            4. Q
            5. Cytochrome C
   5. Complex IV
      1. 160
         1. 13
            1. CuA,CuB , Heme a
            2. 4
            3. O
            4. Cytochrome C
7. 2 special e- carriers
   1. Coenzyme Q
      1. ubiquinone泛醌, ubiquitous quinone苯醌
      2. hydrophobic
      3. accept 2e-
      4. mit. inner mem. (集結成Q-pool: Q & QH2)
      5. mammalian: 10 isoprene units (coenzyme Q10)
         1. 普遍存在心肺肝腎
         2. 隨年齡增長而減少，可考飲食補充
         3. 用於護心、抗癌、抗氧化、抗疲勞（刺激mit產生ATP）
      6. 3 oxidation states -> proton transport
   2. Cytochrome C
      1. 細胞色素, Cyt c
      2. water-soluble protein
      3. accept 1e-
      4. shuttle e-
         1. complex III -> IV
      5. final component 傳遞者，將e-傳給O2
      6. the only e- carrier located in intermembrane space, not in mit. membrane
      7. 演化過程中高度保留
8. Ｏxidoreductase
   1. Oxidase
   2. Dehydrogenase
   3. Hydroperoxidase 氫雙氧酶
      1. peroxidase 過氧化酶
         1. (A: VitC, Q, cyt c)
         2. ex. GPx(glutathione peroxidase)是肝臟的解毒酵素
      2. catalase 過氧化氫酶
   4. Oxygenase
      1. 雙加氧酶 (dioxygenase)
      2. 單加氧酶 (monooxygenase)
9. reactive oxygen species (ROS)
   1. 活性氧分子（具有攻擊的能力）
   2. 非自由基又稱過氧化物