Breathing System/ Gas Exchange

Question 1

Describe the structure of the lungs

Answer 1

The trachea branches into two bronchi
The bronchi branch into bronchioles
These bronchioles end in alveoli which are lined with capillaries for exchange

Question 2

What are the features of an efficient gas
exchange surface?

Answer 2

• Large surface area (diffusion rate increases)
• Thin (short diffusion distance)
• Concentration gradient across surface (maintained by movement of air and transport of gas)
• Moist (allow gases to dissolve)

Question 3

What is the purpose of the cartilage in
the trachea?

Answer 3

The cartilage supports the trachea and
prevents it from closing

Question 4

What chemical can be used to test for
carbon dioxide?

Answer 4

Calcium hydroxide Ca(OH)2 - commonly known as limewater

Question 5

How can limewater be used to test for carbon dioxide?

Answer 5

Lime water is clear but becomes cloudy (or milky) when carbon dioxide is bubbled through it

Question 6

Describe the effects of physical activity on breathing rate and breathing depth

Answer 6

Physical exercise increases heart rate
Respiration is needed to provide energy for muscular contraction.
More oxygen and carbon dioxide are needed for increased rate of respiration.
The heart beats more swiftly to immediately exhale carbon dioxide and provide the muscles more oxygen.

Question 7

What is Respiration?

Answer 7

The chemical reactions that breaks down nutrient molecules in living cells to release energy.

Question 8

Define aerobic respiration

Answer 8

Cellular chemical reactions that use oxygen to break down molecules and release energy

Question 9

What is the equation for aerobic respiration?

Answer 9

Glucose + Oxygen → Carbon dioxide + Water (+ energy)
C 6H 12O 6 + 6O 2 → 6CO 2 + 6H 2O. + ATP

Question 10

Define anaerobic respiration

Answer 10

Chemical reactions in cells that breakdown nutrient molecules to release energy without using oxygen

Question 11

Write the word equation for anaerobic
respiration in muscle cells and yeast

Answer 11

Muscle Cells:
glucose → lactic acid + energy
Yeast:
glucose → alcohol + carbon dioxide +
energy

Question 12

What builds up in muscles during periods of vigorous exercise?

Answer 12

Lactic Acid

Question 13

How is lactic acid removed from the body?

Answer 13

Through aerobic respiration in the liver

Question 14

Which type of respiration produces more
energy?

Answer 14

aerobic

Question 15

What happens to the heart and breathing rate immediately after exercise?

Answer 15

They both remain high to increase the rate of aerobic respiration to remove the lactic acid in the liver