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Fermentation / Anaerobic Respiration

Key Questions

  • Answer:

    Some examples of anaerobic respiration include alcohol fermentation, lactic acid fermentation.

    Explanation:

    Some examples of anaerobic respiration include alcohol fermentation, lactic acid fermentation (which can result in yogurt and in sore muscles), and in decomposition of organic matter. The equation is: glucose + enzymes = carbon dioxide + ethanol/lactic acid.

  • Answer:

    Fermentation is an anaerobic metabolic process in which an organism converts a carbohydrate to an alcohol or an acid.

    Explanation:

    The first step in all fermentation processes is glycolysis, the conversion of glucose to pyruvate:

    #"C"_6"H"_12"O"_6 → "2CH"_3"COCOO"^(−) + "2H"_2"O" + 2"H"^+#

    There are two main types of fermentation; one converts pyruvate into lactate (lactic acid) and the other into ethanol.

    Fermentation
    (from sun.menloschool.org)

    In lactic acid fermentation, pyruvate is converted into lactic acid.

    #underbrace("CH"_3"COCOO"^-)_color(red)("pyruvate") stackrelcolor (blue)("enzymes")(→) underbrace("2CH"_3"CH(OH)COOH")_color(red)("lactic acid") #

    In alcohol fermentation,the pyruvate is decarboxylated to acetaldehyde, and then into ethanol.

    #"CH"_3"COCOO"^(-)+ "H"^+ stackrelcolor (blue)("pyruvate decarboxylase")(→) "CH"_3"CHO" + "CO"_2#

    #"CH"_3"CHO" stackrelcolor (blue)("alcohol dehydrogenase")(⇌) "CH"_3"CH"_2"OH"#

    In an aerobic process, the pyruvate is converted by respiration to carbon dioxide and water.

    Here is a summary of the three possible fates of pyruvate:

    Pyruvate fates
    (rom vishbiochemblog.wordpress.com)

Questions