Describe and name three stages of cellular respiration that aerobic organisms use to obtain energy from glucose.

Explanation

Stages of cellular respiration
(i) Glycolysis : It takes place din cytoplasm of the cell. It is the break down of one molecule of glucose (6 Carbon) into two molecules of Pyruvic acid (3 Carbon).
`{:("Glucose", to, "Pyruvic acid"),("(1molecule)",,"(2molecules)"),(6"carbon",,3"carbon"):}`
(ii) Kreb.s cycle : This occurs in mitochondria matrix . During this cycle, oxidation of pyruvic acid result into `CO_2` and water.
`Pyruvic acid overset("Oxidation")(rarr)CO_2 + H_2O`
(iii) Electron transport chain (ETC):
ETC is located on the inner membrane of the mitochondria.
(a) `NADH_2 and FADH_2` molecules formed during Glycolysis and Kreb.s are oxidised to `NAD^(+) and FAD^(+)` to release the energy via electrons.
(b) The electrons, as they move through the system, release energy which is trapped by ADP to synthesize ATP. This is called Oxidative Phosphorylation. During this process, oxygen which is the acceptor of electrons get reduced to water.