Anaerobic Cellular Respiration

1
Anaerobic Cellular Respiration
2
Anaerobic

• Without oxygen
• No oxygen to act as final electron acceptor in
  electron transport chain of cellular respiration

3
Glycolysis First

• Glycolysis is first step in fermentation
• Breaks down the glucose molecule into 2 pyruvic
  acid molecules
• Produces 2 ATP
• Takes place in cytoplasm no need for membrane
  bound organelles such as mitochondria

4
Lactic Acid Fermentation

• Carried out by human muscle cells when not enough
  oxygen is available most energy is still
  trapped in the lactic acid molecule
• Lactic acid fermentation does not produce carbon
  dioxide
• The lactic acid molecule is later broken down in
  human liver cells into products (pyruvic acid)
  that can be fed into the Krebs cycle

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Lactic Acid (continued)

• Lactic acid fermentation can be carried out by
  certain fungi and bacteria
• Used in dairy industry to produce cheese and
  yogurt
• Can also be used in the production of acetone
  (nail polish remover) and methanol (methyl
  alcohol (poisonous))

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Food Uses
7
Alcohol Fermentation

• Pyruvic acid produced by glycolysis is broken
  down in 2 steps
• 1st release carbon dioxide (important in bread
  rising)
• 2nd step produces ethanol
• Carried out by many bacteria and also by yeast (a
  single celled fungi)

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Ethanol Formula

• C2OH6
• Molecular formula
• Structural formula

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Facultative Anaerobes

• Organisms that use aerobic cellular respiration
  when there is enough oxygen but that switch to
  fermentation when there isnt enough oxygen
• Much more efficient use of sugar when lots of
  oxygen present
• How would you describe human muscle cells?

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The Reactions

• C6H12O6      2 CH3CHOHCOOH 2 ATP
• Glucose lactic acid
• C6H12O6 ? 2 C2H5OH 2 CO2 2 ATP
• Glucose Ethanol

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Yeast

• Bakers yeast
• Saccharomyces cerevisiae
• http//en.wikipedia.org/wiki/FileS_cerevisiae_und
  er_DIC_microscopy.jpg