Chapter 9.3

Question 1

How do organisms generate energy when oxygen is not available?

Answer 1

In the absence of oxygen, fermentation releases energy from food molecules by producing ATP

Question 2

How does the body produce ATP during different stages of exercise?

Answer 2

For short, quick bursts of energy, the body uses ATP already in muscles as well as ATP made by lactic acid fermentation.

For exercise longer that about 90 seconds, cellular respiration is the only way to continue generating a supply of ATP.

Question 3

What are the two types of fermentation?

Answer 3

1) Alcoholic Fermentation - produces ethyl alcohol and carbon dioxide from pyruvic acid and NADH.
2) Lactic Acid Fermentation - produces NAD+ and lactic acid from pyruvic acid. Does not give off carbon dioxide. Since it regenerates NAD+, glycolysis can continue.

Question 4

Humans undergo which type of fermentation?

Answer 4

Lactic Acid fermentation- during brief periods without oxygen, many cells in our bodies are capable of producing ATP through this process. Muscle cells are very adapted to doing this dues to needed large amounts of ATP for rapid bursts of activity.