Question
Explain the process of terminal oxidation. Give its significance $($any two points$).$
✓
Answer
$1. \ NADH_2$ and $FADH_2$ produced during glycolysis, connecting link reaction and Krebs cycle are oxidized with the help of various electron carriers and enzymes.
$2.$These carriers and enzymes are arranged on inner mitochondrial membrane in the form of various complexes as complex $I, II, III, VI$ and $V.$
$3. \ NADH+H^+$ is oxidised by $\text{NADH}$ dehydrogenase $($complex $I)$ and it’s electrons are transferred to ubiquinone $($coenzyme $Q-CoQ)$ present on inner membrane of mitochondria. Reduced ubiquinone is called as ubiqunol.
$4. \ FADH_2$ is oxidised by complex $II ($Succinate dehydrogenase$)$ and these electrons are also transferred to $CoQ$.
$5.$ During oxidation of $NADH^+H^+$ and $FADH_2,$ electrons and protons are released but only electrons are canned forward whereas protons are released into outer chamber of mitochondria $($intermembrane space$).$
$6.$ Ubiquinol is oxidised by complex$-III ($Cytochrome $bcl$ complex$)$ and it’s electrons are transferred to cytochrome $C.$
$7.$ Cytochrome $C$ is a small, iron$-$containing protein, loosely associated with inner membrane. It acts as a mobile electron carrier, transferring the electrons between complex $III$ and $IV.$
$8.$Cytochrome $C$ is oxidised by complex $IV$ or cytochrome $C$ oxidase consisting of cytochrome a and $a_3.$ Electrons are transferred by this complex to the molecular oxygen. This is terminal oxidation.
$9.$ Reduced molecular oxygen reacts with protons to form water molecule called as metabolic water.
$10.$ Protons necessary for this are channelled from outer chamber of mitochondria into inner chamber by $F_0$ part of oxysome $($complex $V)$ present in inner mitochondrial membrane.
$11.$ This proton channelling by $F_0$ is coupled to catalytic site of $F_1$ which catalyses the synthesis of $\text{ATP}$ from $\text{ADP}$ and inorganic phosphate. This is oxidative phosphorylation.
$12.$ As transfer of protons is accompanied with synthesis of $\text{ATP,}$ this process is named as ‘Chemiosmosis’ by Peter Mitchell.
$2.$These carriers and enzymes are arranged on inner mitochondrial membrane in the form of various complexes as complex $I, II, III, VI$ and $V.$
$3. \ NADH+H^+$ is oxidised by $\text{NADH}$ dehydrogenase $($complex $I)$ and it’s electrons are transferred to ubiquinone $($coenzyme $Q-CoQ)$ present on inner membrane of mitochondria. Reduced ubiquinone is called as ubiqunol.
$4. \ FADH_2$ is oxidised by complex $II ($Succinate dehydrogenase$)$ and these electrons are also transferred to $CoQ$.
$5.$ During oxidation of $NADH^+H^+$ and $FADH_2,$ electrons and protons are released but only electrons are canned forward whereas protons are released into outer chamber of mitochondria $($intermembrane space$).$
$6.$ Ubiquinol is oxidised by complex$-III ($Cytochrome $bcl$ complex$)$ and it’s electrons are transferred to cytochrome $C.$
$7.$ Cytochrome $C$ is a small, iron$-$containing protein, loosely associated with inner membrane. It acts as a mobile electron carrier, transferring the electrons between complex $III$ and $IV.$
$8.$Cytochrome $C$ is oxidised by complex $IV$ or cytochrome $C$ oxidase consisting of cytochrome a and $a_3.$ Electrons are transferred by this complex to the molecular oxygen. This is terminal oxidation.
$9.$ Reduced molecular oxygen reacts with protons to form water molecule called as metabolic water.
$10.$ Protons necessary for this are channelled from outer chamber of mitochondria into inner chamber by $F_0$ part of oxysome $($complex $V)$ present in inner mitochondrial membrane.
$11.$ This proton channelling by $F_0$ is coupled to catalytic site of $F_1$ which catalyses the synthesis of $\text{ATP}$ from $\text{ADP}$ and inorganic phosphate. This is oxidative phosphorylation.
$12.$ As transfer of protons is accompanied with synthesis of $\text{ATP,}$ this process is named as ‘Chemiosmosis’ by Peter Mitchell.
Need a full question paper?
Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.
Explore more
Similar questions
With help of neat labelled diagram, describe the structure of areolar connective tissue.
Draw neat and labelled diagram of Funaria.
Describe the structure of mitochondria.
What are the various types of plastids? ii. Describe the chemical composition and functions of eukaryotic cell wall.
What is absorption? Mention the absorption of nutrients and other substances in alimentary canal?
Mention the unique features of ctenophores.
What are Carotenoids?
Explain in detail the mechanism of enzyme action. Write a note on model proposed by Emil Fischer for mechanism of enzyme action.
Explain histological structure of mammalian bone.