Question

what are the different ways in which glucose is oxidized to provide energy in various organism
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Answer 1

1) Anaerobic respiration: Here the first step is the break-down of glucose into a three-carbon molecule called pyruvate. This process takes place in the cytoplasm. Further, the pyruvate may be converted into ethanol and carbon dioxide. This process takes place in yeast.

 

2) Aerobic respiration : During aerobic respiration, first glucose is broken down into pyruvate and then  the three-carbon pyruvate molecule is broken down to give three molecules of carbon dioxide and water.

Answer 2

Pyruvate (3 carbon molecule) is formed by glucose (6 carbon molecule) through Glycolysis in all the organisms. Anaerobic Respiration: Anaerobic respiration in microbe such as yeast which is also known as fermentation produce end-products as follows:

C6H12O6 ----> Pyruvate ----> 2C2H5OH + 2CO2 + Energy

Aerobic respiration:

The second step of respiration in human cell takes place in the presence of oxygen inside mitochondria and is, therefore, called aerobic (in air) respiration. During this stage, the end product of glycolysis, the 2 molecules of pyruvic acid enter the mitochondria of aerobic cells and undergo complete oxidation by enzymes in Krebs cycle into CO2 and H2O and release large amount of energy (30 ATP molecules). Thus, complete oxidation of one molecule of glucoseand aerobic respiration generates in total of 38 ATP molecules.