Exploring fermentation


Which one of the following statements CANNOT be included while defining the fermentation process?

  1. Alcohol is formed from sugar residues
  2. Requires an electron transport system
  3. Utilizes an organic compound as the final electron acceptor
  4. Produces lactic acid in oxygen deprived muscle

Rephrasing the question:

What are the characteristics of fermentation?


Fermentation does not require an electron transport system (option 2).


There are three ways an organism can derive energy from the organic molecules it consumes: aerobic respiration, anaerobic respiration, and fermentation. For each of these pathways, the first, common step is glycolysis of glucose, producing pyruvate, ATP, and NADH.


What happens next depends on the pathway taken, but in all cases, deriving energy from food requires oxidative steps and so it need a final electron acceptor.

  1. Aerobic respiration requires oxygen. It uses an electron transport chain (ETC), and the final electron acceptor is oxygen (O2).

  2. Anaerobic respiration does not require oxygen, but it still does use an ETC. Its final electron acceptor can be nitrate (NO3), sulphate (SO42), or others. Anaerobic respiration is less efficient than aerobic respiration.

  3. Fermentation, like anaerobic respiration, does not require oxygen. The way it differs is that it also does not use any ETC – so it does not use any cellular respiration. Instead, the final electron acceptor of fermentation is always an organic compound, but a different compound depending on the type of fermentation:

    1. In alcohol fermentation, pyruvate in converted to ethanol. Yeast and some bacteria use this.

    2. In lactic acid fermentation, pyruvate is converted to lactate. Examples are the lactobacilli we use to make yogurt. Lactic acid fermentation is also used by muscles during intense exercise, when O2 levels are low.


4 thoughts on “Exploring fermentation”

  1. Pingback: How to study For the NET: 2 more tips - NET Life Sciences

  2. stumbledupon it 😉 I am going to come back yet
    again since i have book marked it. Money and freedom is the greatest way to
    change, may you be rich and continue to help other people.“강남오피”Thanks for sharing

Leave a Comment

Your email address will not be published.