Ethanol Fermentation - The Chemical Process of Fermentation of Glucose

The Chemical Process of Fermentation of Glucose

The chemical equations below summarize the fermentation of sucrose (C12H22O11) into ethanol (C2H5OH). Alcoholic fermentation converts one mole of sucrose into four moles of ethanol and four moles of carbon dioxide, producing two moles of ATP in the process.

The overall chemical formula for alcoholic fermentation is:

C6H12O6 + Zymase → 2 C2H5OH + 2 CO2

Sucrose is a dimer of two glucose molecules. In the first step of alcoholic fermentation, the enzyme invertase cleaves the glycosidic linkage between the two glucose molecules.

C12H22O11 + H2O + invertase → 2 C6H12O6

Next, each glucose molecule is broken down into two pyruvate molecules in a process known as glycolysis. Glycolysis is summarized by the equation:

C6H12O6 + 2 ADP + 2 Pi + 2 NAD+ → 2 CH3COCOO− + 2 ATP + 2 NADH + 2 H2O + 2 H+

The chemical formula of pyruvate is CH3COCOO−. Pi stands for the inorganic phosphate.

As shown by the reaction equation, glycolysis causes the reduction of two molecules of NAD+ to NADH. Two ADP molecules are also converted to two ATP and two water molecules via substrate-level phosphorylation.


  • Glucose depicted in Haworth projection

  • Pyruvate

  • Acetaldehyde

  • Ethanol

Read more about this topic:  Ethanol Fermentation

Famous quotes containing the words chemical, process and/or fermentation:

    “Ants are so much like human beings as to be an embarrassment. They farm fungi, raise aphids as livestock, launch armies into war, use chemical sprays to alarm and confuse enemies, capture slaves, engage in child labor, exchange information ceaselessly. They do everything but watch television.”
    —Lewis Thomas (b. 1913)

    “The process of discovery is very simple. An unwearied and systematic application of known laws to nature causes the unknown to reveal themselves.”
    —Henry David Thoreau (1817–1862)

    “Two principles, according to the Settembrinian cosmogony, were in perpetual conflict for possession of the world: force and justice, tyranny and freedom, superstition and knowledge; the law of permanence and the law of change, of ceaseless fermentation issuing in progress. One might call the first the Asiatic, the second the European principle.”
    —Thomas Mann (1875–1955)