Difference Between Aerobic Respiration and Fermentation (With Table)

The processes of aerobic respiration and fermentation are both employed to supply energy to cells. In the presence of oxygen, aerobic respiration produces carbon dioxide, water, and energy in the form of adenosine triphosphate (ATP). Fermentation is a method of generating energy in the absence of oxygen. Whether the process is lactic acid fermentation or alcoholic fermentation, the results may be lactic acid and nicotinamide adenine dinucleotide (NAD+) or ethanol, carbon dioxide, etc nicotinamide adenine dinucleotide (NAD+).

Aerobic Respiration vs Fermentation

The main difference between aerobic respiration and fermentation is that aerobic respiration occurs in the presence of oxygen since it is necessary for the breakdown of its respiratory components, whereas fermentation does not. Both of these methods are utilized to obtain energy, but their methods differ.

In the presence of oxygen, aerobic respiration produces adenosine triphosphate (ATP) molecules, which are used as energy for numerous biological tasks. In total, it passes through three stages. Glycolysis, Krebs cycle, and oxidative phosphorylation are the steps involved. Cellular respiration is a type of it.

Fermentation, on the other hand, breaks down sugar molecules into simpler chemicals to make ATP molecules, which are used to carry out biological functions. It occurs when there is a lack of oxygen. It consists of two steps: glycolysis and NADH regeneration, which is the breakdown of pyruvic acid.

Comparison Table Between Aerobic Respiration and Fermentation

Parameters of ComparisonAerobic RespirationFermentation
OrganismsAnimals and plantsYeast and bacteria mainly
OxygenThe respiratory substance is broken down using oxygen.There is no utilization of oxygen.
End ProductsCarbon dioxide and water.Ethyl alcohol and carbon dioxide
Respiratory Material.Completely decomposedIt’s not entirely broken.
Formation of WaterIt has taken shape.It is not commonly formed.
ContinuationIt will continue endlessly.It can’t keep happening indefinitely.
Energy Formed686 Kcal39-59 Kcal
ATP moleculesA total of 36 ATP molecules are created.A total of 2 ATP molecules are created.
StepsThere are three steps to it.There are two steps to it.

What is Aerobic Respiration?

By breaking down respiratory material, aerobic respiration uses oxygen to create energy in the form of ATP molecules. It occurs most frequently in complex creatures such as animals, people, plants, mammals, and so forth. Cellular respiration is a type of it.

Carbon dioxide and water are the major end-products. It takes place in the mitochondrial matrix of the cell. It is critical because it ensures that organisms have adequate energy to carry out their key tasks and processes.

Different phases of aerobic respiration exist. The first stage is glycolysis, which takes place in the cytosol of the cell. Glucose is split into two ATP and two NADH molecules during glycolysis. Acetyl coenzyme A is then produced.

The Krebs cycle (also known as the citric acid cycle) takes place next. Large amounts of ATP molecules are produced during the last stage of aerobic respiration by the transfer of electrons from FADH and NADH. It produces around 36 ATP molecules in the end. With the help of ATP synthase, ATP molecules are made from ADP and inorganic phosphate.

What is Fermentation?

Fermentation is an anaerobic process that involves breaking down glucose to produce ATP molecules in the absence of oxygen. It may be found in a variety of microorganisms, including eukaryotes and prokaryotes. Yeast and bacteria are the most prevalent hosts. It may also happen in people, but only when oxygen is scarce and there is a significant demand for energy, such as during strenuous workouts.

When there is a dearth of oxygen, fermentation occurs in muscle cells in humans. If these cells contract repeatedly, they can deplete their oxygen supply. They manufacture ATP molecules by glycolysis in the absence of oxygen. These muscle cells produce pyruvic acid from glucose, which is then converted to pyruvic acid by a muscle cell enzyme.

Through the process of glycolysis, glucose is metabolized (i.e. broken down into) pyruvic acid in fermentation. Acetaldehyde is formed when pyruvic acid is transformed. After that, it’s turned into ethyl alcohol. Fermentation produces an average of 2 ATP molecules per reaction.

Main Differences Between Aerobic Respiration and Fermentation

  1. Aerobic respiration is most commonly seen in multicellular and complex organisms, such as animals and plants. Fermentation, on the other hand, is mostly carried out by microorganisms such as yeast and bacteria.
  2. Aerobic respiration occurs when the respiratory material is broken down into simpler components with the aid of oxygen. In the breakdown of its respiratory ingredient, fermentation does not need oxygen.
  3. The end products of aerobic respiration are carbon dioxide and water, whereas the end products of fermentation are at least one organic material and may or may not include inorganic chemicals. The most typical end products are ethyl alcohol and carbon dioxide.
  4. In aerobic respiration, the respiratory material is entirely oxidized, but in fermentation, it is only partially broken.
  5. Water is created during aerobic respiration, however, it is not formed during fermentation.
  6. Aerobic respiration can go on indefinitely, however, fermentation can’t since it can lead to a reduction in energy availability and the buildup of toxic chemicals.
  7. The energy generated by aerobic respiration is 686 Kcal per gram mole of glucose, but the energy produced by fermentation is roughly 39 to 59 Kcal.
  8. During aerobic respiration, 36 ATP molecules are produced. Fermentation, on the other hand, produces just two ATP molecules.
  9. Krebs’ cycle, glycolysis, and oxidative phosphorylation are the three phases of aerobic respiration. Glycolysis and an incomplete breakdown of pyruvic acid are the only two processes in fermentation.


In distinct methods, aerobic respiration and fermentation are both employed to supply energy to organisms. Aerobic respiration occurs mostly in animals and plants when oxygen is present, whereas fermentation happens primarily in yeast and bacteria when oxygen is not present.

Both of these processes are equally significant since they perform somewhat different tasks and go through various phases.


  1. https://academic.oup.com/femsle/article-abstract/71/1-2/123/556548
  2. https://www.annualreviews.org/doi/abs/10.1146/annurev-food-022811-101255