Cell Respiration

Question 1

What is cell respiration?

Answer 1

The controlled release of energy from organic compounds to produce ATP.

Question 2

What are the two types of respiration?

Answer 2

1. Anaerobic respiration involves the partial breakdown of glucose in the cytosol for a small yield of ATP
2. Aerobic respiration utilizes oxygen to completely breakdown glucose in the mitochondria for a larger ATP yield

Question 3

What is ATP?

Answer 3

Adenosine triphosphate (ATP) is a high energy molecule that functions as an immediate source of power for cellular processes

Question 4

When is anaerobic respiration useful?

Answer 4

1. When a short but rapid burst of ATP production is needed
2. When oxygen suppliers run out
3. In environments that are deficient in oxygen

Question 5

Why is anaerobic respiration used during exercise?

Answer 5

When exercising at high intensity, the cells’ energy demands will exceed what the available levels of O2 can supply aerobically.
Anaerobic respiration can supply ATP at a rapid overall rate for a short time as it is not dependent on oxygen.

Question 6

What is the consequence of respiring anaerobically?

Answer 6

Anaerobic respiration will result in an increase in the production of lactic acid, which leads to muscle fatigue.

Question 7

What is oxygen debt?

Answer 7

The demand for oxygen that builds up during a period of anaerobic respiration, so as to convert the lactic acid back to pyruvate when at rest

Question 8

What is fermentation?

Answer 8

Anaerobic respiration in yeast/bacteria, results in the production of ethanol and carbon dioxide

Question 9

What are the applications of fermentation?

Answer 9

1. CO2 and the baking industry
   - CO2 produced by fermentation forms bubbles, making the dough rise, increasing its volume and making it less dense
   - When the dough is baked, the ethanol evaporates, and the CO2 bubbles give the bread a light texture
2. Ethanol and the brewing & biofuels industry
   - Ethanol is the intoxicating agent in alcoholic beverages
   - Ethanol is also used as a fuel
3. Bacteria & food industry
   - Bacteria produce lactic acid, which aids in the production of yogurts and cheese

Question 10

What is a respirometer?

Answer 10

A respirometer is any device that is used to measure respiration rates

Question 11

What are the parts of a respirometer?

Answer 11

1. Sealed glass in which the organism or tissue is placed
2. An alkali, such as potassium hydroxide, which absorbs CO2 produced by cell respiration
   - This way, the volume of air inside the respirometer should reduce during cellular respiration (as oxygen is depleted)
3. Capillary tube containing fluid, which allows the volume of air inside the respirometer to be monitored

Question 12

What factors might affect respiration rate?

Answer 12

1. Temperature
2. Hydration
3. Light
4. Age
5. Activity levels