13. Respiration and Energy Transfer - part 03 - Aerobic Respiration

 


13. Respiration and Energy Transfer - part 03 - Aerobic Respiration


Aerobic Respiration :

  • Aerobic respiration involves molecular oxygen as final electron acceptor which are liberated during oxidation of glucose. 
  • Glucose is completely oxidized in this process which is operated through steps like 
  1. glycolysis
  2. production of acetyl CoA (connecting link reaction)
  3. Krebs cycle
  4. electron transfer chain reaction and terminal oxidation.



    Glycolysis :
    • First step of aerobic respiration i.e. glycolysis .
    • In case of aerobic respiration, glycolytic product i.e. pyruvic acid is converted into actyl CoA.
    • This process occurs in cytoplasm in case of prokaryotes and in mitochondria in case of eukaryotes.

    Conversion of pyruvic acid to Acetyl CoA :


    • This is an oxidative decarboxylation reaction. 
    • It is catalyzed by a multienzyme complex - pyruvate dehydrogenase complex (PDH). 
    • This enzyme is present in mitochondria of eukaryotes and cytosol of prokaryotes.This reaction is called as 'connecting link' reaction between glycolysis and Krebs cycle.


    Do you know?

    • Pyruvate dehydrogenase complex needs thiamin (vitamin B1) as a co-enzyme.
    • It can not function in absence of vitamin B1. Hence, thiamin deficiency causes pyruvic acidosis and lactic acidosis, the life threatening conditions. 
    • Hence balanced diet is very important in maintenance of health.

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