question_answer

What are the different ways in which glucose is oxidised to provide energy in various organisms?      

Answer:

                (i) The first steps is the breakdown of 6-carbon molecule glucose into a 3-carbon molecule pyruvate. This process takes place in the cytoplasm. (ii) Further oxidation of pyruvate occurs in the following ways In yeast, pyruvate is converted into ethanol and carbon dioxide in the absence of oxygen. (b) In our skeletal muscles, pyruvate is converted into lactic acid, when there is deficiency/lack of oxygen. (c) The aerobic oxidation of pyruvate occurs in the mitochondria; the 3-carbon pyruvate molecule gives rise to three molecules of carbon dioxide and water.                (5)