Question

how is glucose oxidised write the three step or write three types of respiration

Answer 1

During fermentation, a chemical called nicotinamide adenine dinucleotide + hydrogen (NADH) is oxidized and a chemical called pyruvate is reduced. This process produces only two ATP molecules per glucose molecule, while cellular respiration produces 36 ATP molecules from a single glucosemolecule.

Answer 2

✳️➡️At first glucose (6 carbon molecules) is broken in the cytoplasm of cells of all organisms. This process yields a 3 carbon molecule compound called pyruvate.
Further break down of pyruvate takes place in different manners in different organisms.⬅️✳️

1. Anaerobic Respiration
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.

2. Aerobic Respiration
In aerobic respiration, breakdown of pyruvate takes place in presence of oxygen to give rise 3 molecules of carbon dioxide and water. The release of energy in aerobic respiration is much more than anaerobic respiration.

3. Lack of Oxygen
Sometimes, when there is lack of oxygen, especially during vigorous activity, in our muscles, pyruvate is converted into lactic acid (3 carbon molecule compounds). Formation of lactic acid in muscles causes cramp.