Lesson Summary:
When oxygen is absent, aerobic respiration cannot continue because the electron transport chain stops. However, cells can still make ATP through anaerobic pathways like lactate fermentation in animals and ethanol fermentation in yeast and some plants. These processes recycle NAD so glycolysis can continue. Rice, a flood-tolerant plant, adapts to low-oxygen conditions by using ethanol fermentation and developing air spaces (aerenchyma) in its tissues.

Three Things Students Must Learn:

  1. Anaerobic respiration includes lactate fermentation (in animals) and ethanol fermentation (in yeast/plants).

  2. These processes regenerate NAD, allowing glycolysis to continue and produce ATP without oxygen.

  3. Rice adapts to flooded, low-oxygen environments using aerenchyma and ethanol fermentation to survive.