Aerobic and Anaerobic Respiration

Objectives

• Distinguish aerobic from anaerobic
• Explain the benefits of fermentation

Types of Cellular Respiration

• Aerobic - in presence oxygen
• Anaerobic - in absence of oxygen
• Both begin with glycolysis

Fermentation is an important way of making ATP without oxygen.

Fermentation involves glycolysis but not the Krebs cycle or electron transport.

Lactic Acid Fermentation

• Pyruvic acid -> lactic acid
• NADH -> NAD+
• Bacteria in yogurt
• Occurs in muscles cells

Alcoholic Fermentation

• Pyruvic acid -> alcohol + CO2
• NADH -> NAD+
• Done by yeasts and bacteria

Forming NAD+ allows glycolysis to continue.

However, the only ATP molecules made are the two during glycolysis. Aerobic respiration makes 38 total ATP.

This may explain why organisms dominate life on Earth.

Advantages of Anaerobic Respiration

• Life where there is little or no oxygen
• Speed - produces ATP quickly