Name 	   Class 	    Date 	

9.3 Fermentation
A. The chart below shows the key term in this lesson with its definition. Complete the chart by writing a strategy to help you remember the meaning of the term.

Term	Definition	How I’m Going to Remember the Meaning	
Fermentation	The anaerobic process that releases energy from food molecules by producing ATP		

Venn Diagram A Venn diagram is made up of overlapping circles. It is a useful tool for comparing two or even three topics. As you read about the two forms of fermentation in Lesson 3, complete the Venn diagram below.

Fermentation
Fermentation is respiration without oxygen. In fermentation, energy is released from food molecules by producing ATP. There are two forms of fermentation: alcoholic fermentation and lactic acid fermentation. Alcoholic fermentation is what makes bread rise. It is also used in alcoholic beverages. Lactic acid fermentation is used to produce foods such as cheese, yogurt, pickles, and kimchi. The diagram below shows the two types of fermentation.
Follow the directions.
1. Label the process that shows alcoholic fermentation.
2. Label the process that shows lactic acid fermentation.

Glycolysis

CYTOPLASM

Glucose

NAD+ cycles back

NAD+ cycles back

2 Pyruvic Acid

2 CO2

2 Ethyl Alcohol

2 Lactic Acid

Circle the correct answer. Questions may have more than one correct answer.
3. Alcoholic fermentation is used to make which product?
bread	cheese	yogurt	pickles
4. What kind of taste do lactic acid bacteria give foods?
sweet	salty	sour	spicy
5. What are some milk products made from lactic acid fermentation?
milk	sour cream	yogurt	cheese
6. What is one main difference between fermentation and aerobic respiration?

The two main types of fermentation are named for the products they form.
Complete the chart.

	Lactic Acid Fermentation	Alcoholic Fermentation	
Reactants			
End products			
Uses by humans			

Energy and Exercise
Humans have three sources of ATP. There is ATP stored in muscles, ATP made by lactic acid fermentation, and ATP made during cellular respiration. When short bursts of energy are needed, the body uses the ATP stored in muscles and ATP made by lactic acid fermentation.
Cellular respiration is the only way to produce enough ATP for exercise longer than about 90 seconds. The timeline below represents the amount of time a person has been running. The time increments are in 30-second intervals for a total of 6 minutes.
Color the part of the run when energy is most likely supplied by lactic acid fermentation.

Minutes

0

0.5

1.5

2.5

3.5

4.5

5.5

1

2

3

4

5

6

Answer the questions.
1.	 At what time does the runner’s body switch from energy supplied by lactic acid to energy supplied by cellular respiration? 	

2. Circle the correct answer. Which process gives a runner more energy?
cellular respiration	lactic acid fermentation

3. Circle the correct answer. You are in a race that lasts 25 minutes. Where will your body get the energy it needs?
breakdown of glucose	breakdown of fats

4. Compare the ATP production of a sprinter and that of a long-distance runner.