Theory:

The process of aerobic respiration occurs in three different stages:
  1. Glycolysis
  2. Krebs cycle
  3. Electron transport chain
Aerobicmitochondriaprocesss.png
The process of cellular respiration
1. Glycolysis (Glucose splitting):
  • Both aerobic and anaerobic respiration begin with this process.
  • During this process, one molecule of glucose (6 carbon) is broken down into two pyruvic acid molecules (3 carbon).
  • It occurs in the cytoplasm of the cell.
The_process_of_Glycolysis_(source_https---www.s-cool.co.uk-a-level-biology-respiration-revise-it-glycolysis_).gif
Steps involved in glycolysis
2.  Krebs cycle:
  • It is the second stage of cellular respiration and occurs in the mitochondrial matrix.
  • Sir Hans Krebs discovered it. Hence it is known as the Krebs cycle.
  • The two molecules of pyruvic acid produced in the glycolysis enter into the mitochondria after glycolysis.
  • During this cycle, pyruvic acid is oxidized into \(CO_2\) and water.
  • Krebs cycle is also known as the Tricarboxylic Acid Cycle (TCA).
800px-Respiration_diagram.png
Pictorial representation of Krebs cycle and ETC
3. Electron Transport Chain:
Figure_07_04_01.jpg
  • This involves a system of electron transport chain (ETC) found on the inner mitochondrial membrane.
  • During this, the \(NADH_2\) and \(FADH_2\) molecules produced in the glycolysis and Krebs cycle are oxidized to \(NAD^+\) and \(FAD^+\) to release the energy via electrons.
  • As these electrons move through the system of the electron chain, they release the energy that the ADP traps to synthesize ATP. This is known as oxidative phosphorylation as a phosphate group is added to ATP.
  • \(O_2\) serves as the final acceptor electrons and thereby gets reduced to water.
Reference:
https://upload.wikimedia.org/wikipedia/commons/e/e2/Figure_07_04_01.jpg
https://commons.wikimedia.org/wiki/File:The_process_of_Glycolysis_(source_https---www.s-cool.co.uk-a-level-biology-respiration-revise-it-glycolysis_).gif
https://commons.wikimedia.org/wiki/File:Aerobic_mitochondria_process.png