Question

What are the three different ways by which glucose is broken down in living world?

Answer 1

1) Aerobic respiration : In this case pyruvate is broken down into water and carbon dioxide along with release of energy. It commonly occurs in mitochondria of cells.
2) Anaerobic respiration in yeast : In yeast cells during fermentation pyruvate is converted into ethanol and C02 in the absence of 02.
3) Anaeorbic respiration in muscles: Due to lack of oxygen, eg. during vigorous running or exercise, in human muscles, pyruvate is converted to lactic acid.