1. Fermentation is an alternative pathway of cellular respiration in breaking down glucose without the presence of oxygen
2. The breaking down of glucose through fermentation is incomplete and only taken place in the cytoplasm
3. Fermentation can occur in human muscle cells, yeasts, plants, and certain bacteria such as Lactobacillus
4. Fermentation can be divided into two: lactic acid and alcohol fermentation

• Glucose is broken down into pyruvic acid through glycolysis and then broken down into lactic acid
• There are only two ATP molecules formed during glycolysis
• Example:
  • Lactobacillus such as yogurt
  • Human muscle cells

• Glucose is broken down into pyruvic acid through glycolysis and then broken down into ethanol and carbon dioxide
• There are only two ATP molecules formed during glycolysis
  • Yeast
  • Plant such as paddy plant

• The breakdown process of glucose and its conversion to chemical energy.
• Produces chemical energy in the form of ATP.
• The process begins in the cytoplasm.
• The process begins with glycolysis where glucose is converted to pyruvate.
• Occurs in yeast, bacteria, animals, and plants.

The breakdown process of glucose is completed in the presence of oxygen.

The breakdown process of glucose is incomplete without oxygen or in limited oxygen conditions.

Occurs in the cytoplasm and mitochondrion.

Occurs in the cytoplasm.

Produces water

Does not produce water

Glucose is oxidized completely into carbon dioxide and water

Glucose is not oxidized completely into ethanol and carbon dioxide or lactic acid.

One molecule of glucose generates 2898 kJ of energy.

One molecule of glucose generates 210 kJ (alcohol fermentation) or 150 kJ (lactic acid fermentation) of energy.