Botany - Respiration in Plants Question with Solution | TestHub

Aerobic respiration is the process that leads to the complete oxidation of organic substances in the presence of oxygen and releases ${\mathrm{CO}}_2,$ water, and a large amount of energy present in the substrate. The crucial events in aerobic respiration are:

• The complete oxidation of pyruvate by the stepwise removal of all the hydrogen atoms, leaving three molecules of ${\mathrm{CO}}_2$
• The passing on of the electrons removed as part of the hydrogen atoms to molecular ${\mathrm{O}}_2$ with the simultaneous synthesis of ATP.

When the electrons pass from one carrier to another via complex I to IV in the electron transport chain, they are coupled to ATP synthase (complex V) to produce ATP from ADP and inorganic phosphate. The number of ATP molecules synthesised depends on the nature of the electron donor. Oxidation of one molecule of NADH gives rise to 3 molecules of ATP, while that of one molecule of ${\mathrm{FADH}}_2$ produces $2$ molecules of ATP. Although the aerobic process of respiration takes place only in the presence of oxygen, the role of oxygen is limited to the terminal stage of the process.