1. KEY CONCEPT Fermentation allows the production of a small amount of ATP without oxygen.

2. Objectives
Describe the process of fermentation.
Summarize the importance of fermentation.

3. Vocabulary
Fermentation
Anaerobic process by which ATP is produced by glycolysis.
Lactic Acid
Product of fermentation in many types of cells, including human muscle cells.

4. Fermentation allows glycolysis to continue.
Fermentation allows glycolysis to continue making ATP when oxygen is unavailable.
Fermentation is an anaerobic process.
occurs when oxygen is not available for cellular respiration
does not produce ATP

5. Fermentation allows glycolysis to continue making ATP when oxygen is unavailable.
NAD+ is recycled to glycolysis
Lactic acid fermentation occurs in muscle cells.
glycolysis splits glucose into two pyruvate molecules
pyruvate and NADH enter fermentation
energy from NADH converts pyruvate into lactic acid
NADH is changed back into NAD+

6. Fermentation and its products are important in several ways.
Alcoholic fermentation is similar to lactic acid fermentation.
glycolysis splits glucose and the products enter fermentation
energy from NADH is used to split pyruvate into an alcohol and carbon dioxide
NADH is changed back into NAD+
NAD+ is recycled to glycolysis

7. Fermentation is used in food production.
yogurt
cheese
bread

8. By carb-loading, eating carbohydrate-rich foods.
Question/Answer
How do long-distance runners, such as marathoners, provide the energy their bodies need for a race?
By carb-loading, eating carbohydrate-rich foods.
What has happened to a runner who “hits the wall”?
The carbohydrates are depleted. The body now burns more fat, which requires more oxygen, energy, and time to burn.
“Hitting the wall” means a runner is making ATP through glycolysis and fermentation.
Which process must happen first, fermentation or glycolysis? Explain.
Glycolysis must occur first because fermentation require pyruvate and NADH.

9. Question/Answer
How are alcoholic fermentation and lactic acid fermentation similar?
They both begin with glycolysis of glucose and produce ATP and NAD+
How are the different?
Lactic acid fermentation produces lactic acid; alcoholic fermentation produces alcohol and carbon dioxide.
Explain the importance of alcoholic fermentation in the production of bread’s light, fluffy texture.
Carbon dioxide produced from alcoholic fermentation creates gas pockets in the bread, which cause the bread to rise.