Topic 5 Respiration And Breathing

Question 1

Breathing/ventilation

Answer 1

The physical process of moving air in and out of the lungs, allowing gas exchange with the blood

Question 2

Respiration

Answer 2

The chemical process by which cells break down glucose in the presence of oxygen to produce energy, carbon dioxide and water. It is exothermic and takes place in the mitochondria

Question 3

Why is respiration exothermic?

Answer 3

Energy can be released as heat. It can also be used for growth, reproduction, movement and active transport

Question 4

Aerobic respiration (include word equation and balanced word equation)

Answer 4

Occurs when oxygen is present.
Word equation: glucose + oxygen —> carbon dioxide + water + energy
Balanced word equation: C6H12O6 + 6O2 —> 6CO2 + 6H2O + energy (apt)

Question 5

Anaerobic respiration

Answer 5

Occurs without oxygen. There are two types

Question 6

What are the types of anaerobic respiration?

Answer 6

Mammal and yeast

Question 7

Mammalian Anaerobic respiration (word equation)

Answer 7

Glucose —> lactic acid + energy
Lactic acid builds up which causes pain and fatigue. It is poisonous, and breathing in more oxygen is required to break it down

Question 8

Yeast anaerobic respiration (word equation)

Answer 8

Glucose —> ethanol + carbon dioxide + energy
Used in baking as carbon dioxide create air pockets
Used in brewing due to ethanol production

Question 9

Energy yield in all types of respiration

Answer 9

Aerobic - high
Anaerobic (mammal) - low
Anaerobic (yeast) - low

Question 10

Nasal cavity

Answer 10

Air is filtered and warmed before travelling to lungs

Question 11

Trachea

Answer 11

Carries air to and from the lungs

Question 12

Bronchi

Answer 12

Delivers air directly to each of the 2 lungs

Question 13

Bronchiole

Answer 13

Deliver air to all parts of the lung

Question 14

Alveoli

Answer 14

Site of gas exhange

Question 15

Lungs

Answer 15

The organs of gas exchange

Question 16

Diaphragm

Answer 16

Moves up and down during breathing

Question 17

Ribs

Answer 17

Protects delicate organs in the thorax and moves during breathing

Question 18

Intercostal muscles

Answer 18

Contract and relax, moving rib cage during breahting

Question 19

Pleural cavity/fluid

Answer 19

Lubricates movement of lungs, reducing friction

Question 20

What happens during inhalation?

Answer 20

Diaphragm contracts and flattens
Intercostal muscles contract which lifts ribcage up and out
Increased thoracic volume
Decrease in internal air pressure
Air forced into lungs to equalise pressure

Question 21

What happens during exhalation?

Answer 21

Diaphragm relaxes into a dome shape
Intercostal muscles relax which lowers ribcage down and in
Decreased thoracic volume
Increase in internal air pressure
Air forced out of lungs to equalise pressure

Question 22

How are alveoli adapted for gas exchange?

Answer 22

Large surface area - vast area for gas exchange
Thin walls - are one cell thick which minimises diffusion distance
Moist - dissolves gases which enhances diffusion
Permeable - allows rapid gas movement
Steep concentration gradient - continuous blood flow maintains gradient (high oxygen levels and low carbon dioxide levels in alveoli, but low oxygen levels and high carbon dioxide levels in the blood)

Question 23

Effect of exercise on breathing

Answer 23

Muscles require more oxygen for energy
More carbon dioxide is produced
Breathing rate and depth increase
Sometimes anaerobic respiration is needed for faster energy production, leafing to lactic acid build up (and an oxygen debt)

Question 24

Fit vs unfit people

Answer 24

Fitter people have a lower resting heart rate (their heart is more efficient at pumping blood)
Faster recovery time is a sign of better cardiovascular fitness (heart/muscles can remove waste more quickly)
Unfit people experience a greater heart rate increase (heart/muscles need to work harder to supply oxygen)
Regular exercise can improve heart efficiency, lower resting heart rate and shorten recovery time