question_answer 7)

Distinguish between the following (a) Aerobic respiration and anaerobic respiration (b) Glycolysis and fermentation (c) Glycolysis and citric acid cycle  

Answer:

  (a)      Differences between Aerobic and Anaerobic Respiration

S.N.	Aerobic Respiration	Anaerobic Respiration
1. 2.   3. 4   5.	Presence of oxygen is essential. Complete oxidation of substrates occurs into CO2 and H2O.   End products are non-toxic. Involves glycolysis, Krebs' cycle     and terminal oxidation,              36 ATP molecules are produced from each glucose molecule.	Occurs without oxygen. Incomplete degradations of substrates. End products are toxic when accumulated in large amount.  Involves only glycolysis followed by incomplete breakdown of pyruvic' acid. Only two molecules of ATP are produced from each glucose molecule,

(b)      Differences between Glycolysis and Fermentation 

S.N	Glycolysis	Fermentation
1.     2.       3.	It occurs in cytoplasm of the cell and in all living things. .   Glucose undergoes partial oxidation to form two molecules of pyruvic acid.   The end products are CO2, H2O  - and energy,	It occurs in yeast and muscle cells in animals when oxygen is not sufficient .for cellular respiration. The enzyme like pyruvic acid decarboxylase and alcohol dehydrogenase catalyse these reactions. The end products are CO2 and ethanol and in animal cells lactic acid is released.

(c)       Refer to Ans. 1 (b) in this chapter.