Question

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

Answer 1

This process takes place in absence of oxygen, e.g. in yeast during fermentation. In this case pyruvate is converted into ethanol and carbon dioxide.respiration, breakdown of pyruvate takes place in presence of oxygen to give rise 3 molecules CO2 And H20

Answer 2

there are two different ways in which glucose is oxidised:
1)aerobic repiration(oxygen)
breaking down of pyruvate using oxygen takes place in mitochondria.This process breaks up the three-carbon pyruvate molecule to give three molecules of carbon dioxide.this process is done in presence of oxygen.
2)anerobic repiration(without oxygen)
the breaking of six carbon molecule, into three-carbon molecule called pyruvate.This process takes place in cytoplasm.Further, the pyruvate may be converted into ethanol and carbon dioxide.this process is done in absence of oxygen.