Q.Explain the mechanism of anaerobic respiration.

Aerobic respiration completely oxidises one molecule of glucose using six molecules of oxygen to yield six molecules each of carbon dioxide and water, releasing energy that is largely trapped as ATP.

Respiration is the catabolic process by which cells break down organic food molecules (typically glucose) to release the chemical energy stored in their bonds, using it to synthesise ATP for cellular work. In aerobic respiration, this breakdown goes to completion using molecular oxygen as the final electron acceptor, via the sequential pathways of glycolysis, the link reaction, the Krebs cycle, and oxidative phosphorylation (electron transport chain).

Summing across all these stages, the net overall equation is:

C6H12O6 + 6O2 → 6CO2 + 6H2O + Energy

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Aerobic respiration is summarised by the equation C6H12O6 + 6O2 -> 6CO2 + 6H2O + Energy, representing the complete oxidative breakdown of glucose using oxygen, releasing CO2, water, and usable chemical energy (ATP).

Respiration is the biological process by which cells break down organic food molecules (typically glucose) to release energy for cellular work. In its complete, aerobic form (requiring oxygen), the overall (summary) chemical equation is:

C6H12O6 (glucose) + 6O2 (oxygen) -> 6CO2 (carbon dioxide) + 6H2O (water) + Energy

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Aerobic and anaerobic respiration differ chiefly in their oxygen requirement, end products, energy yield, and cellular site.

Two clear differences:

1. Oxygen requirement and end products: Aerobic respiration requires molecular oxygen and completely oxidises glucose to carbon dioxide and water. Anaerobic respiration occurs in the absence of oxygen and only partially breaks down glucose, producing ethanol and CO2 (alcoholic fermentation, e.g., in yeast) or lactic acid (e.g., in fatigued muscle cells). …

Bacteria respire either aerobically (using O2 as the final electron acceptor) or anaerobically (using an inorganic acceptor other than O2); aerobic respiration, explained below, gives complete oxidation and a high ATP yield.

Bacterial respiration is of two types, depending on the terminal electron acceptor used in the electron transport chain:

1. Aerobic respiration — molecular oxygen (O2) acts as the final electron acceptor. The respiratory substrate (e.g. glucose or another organic compound) is completely oxidised all the way to CO2 and H2O, releasing a large amount of energy that is trapped as a high yield of ATP. Examples: chemoautotrophic bacteria such as Nitrobacter and Nitrosomonas, and most free-living heterotrophic aerobic bacteria.
2. Anaerobic respiration — an inorganic substance OTHER than O2 (such as nitrate, sulphate, or carbonate) serves as the terminal electron acceptor. The substrate is only incompletely oxidised, so the energy released — and hence the ATP yield — is much lower than in aerobic respiration. Examples: denitrifying bacteria (use nitrate) and sulphate-reducing bacteria (use sulphate). …