Breathing And Respiration

Question 1

Why is alveoli adapted for gas exchange?

Answer 1

• they provide a very large surface area, richly supplied with blood capillaries, so that gases can readily diffuse into and out of the blood

Question 2

What is the word and symbol equation for aerobic respiration?

Answer 2

• glucose + oxygen ➡️ carbon dioxide + water (+ energy)

- C6H12O6 + 6O2 ➡️ 6CO2 + 6H2O (+ energy)

Question 3

What happens during exhalation?

Answer 3

• the intercostal muscles relax, so the ribcage moves down
• the diaphragm relaxes and becomes dome-shaped again
• these two movements causes the thorax volume to decrease
• this increases the pressure, so air leaves the lungs

Question 4

What do plants and some microorganism produce during anaerobic respiration?

Answer 4

• they produce ethanol and Co2 instead of lactic acid

Question 5

What is the advantage of anaerobic respiration?

Answer 5

You can keep using your muscles for a while longer

Question 6

What is respiration?

Answer 6

• Respiration is the process of releasing energy from glucose, which goes on in every cell

Question 7

What is the thorax?

Answer 7

• the top part of the body

- separated from the lower part (abdomen) by the diaphragm

Question 8

What is the word and symbol equation of anaerobic respiration?

Answer 8

• glucose ➡️ lactic acid (+ energy)

- C6H12O6 ➡️ 2C3H6O3 (+ energy)

Question 9

Which type of respiration goes on all the time in plants and animals?

Answer 9

Aerobic respiration

Question 10

What are the downsides of anaerobic respiration?

Answer 10

• it is not the best way to convert glucose into energy because lactic acids holds up in the muscles, causing pain.
• also causes muscle fatigue: they get tired and stop contracting efficiently.
• it does not release nearly as much energy as aerobic respiration

Question 11

What happens during inhalation?

Answer 11

• the intercostal muscles contract, pulling the ribcage up
• the diaphragm muscles contract and flattens out
• these two movements cause the thorax volume to increase
• this decreases the air pressure inside the lungs, so it is less than atmospheric pressure outside.
• this draws air in

Question 12

What happens to glycogen during exercise?

Answer 12

• during vigorous exercise, muscles use glucose rapidly, so some of the store glycogen is converted back to glucose to provide more energy.

Question 13

What is anaerobic respiration?

Answer 13

• it is the incomplete breakdown of glucose, which causes a build up of lactic acid.

Question 14

What happens when there is an increase in muscle activity?

Answer 14

• more glucose and oxygen needs to be supplied to muscles cells and extra carbon dioxide to be removed.
• therefore, blood has to flow at a faster rate
• breathing rate increases, making us breather more deeply to meet demand for extras oxygen. Heart rate increases to increase blood flow.

Question 15

Where does aerobic respiration occur?

Answer 15

• mostly inside the mitochondria

Question 16

Why would someone need an artificial/mechanical ventilator?

Answer 16

• under general anaesthetic
• have a lung injury
• have a lung disease

Question 17

What is oxygen debt and how do you repay it?

Answer 17

• after anaerobic respiration, you have to repay the oxygen that you didn’t get to your muscles in time because the lungs, heart and blood couldn’t keep up with the demand earlier on
• you have to keep breathing hard even after you stop to get more oxygen into the blood.
• blood flows through your muscles to remove the lactic acid by oxidising it to harmless co2 and water
• while high levels of Co2 and lactic acid are detected in the blood, pulse and breathing rate stay high

Question 18

Describe a negative pressure ventilator

Answer 18

• a sealed case is placed around a patient’s chest
• air is pumped out of the case, so the pressure drops around the chest.
• this makes the lungs expand and air is drawn into them.
• air is then pumped into the case to produce the opposite effect; air leaves the lungs

Question 19

What is aerobic respiration used for?

Answer 19

• to build up larger molecules from smaller ones (such as proteins from amino acids)
• in animals, to allow muscles to contract
• in mammals and birds, the energy is used to keep their body temperature steady in colder surroundings.
• in plants, it’s used to build sugars, nitrates and other nutrients into amino acids, which are then built up into proteins.

Question 20

• which type of respiration is the most efficient way to release energy from glucose?

Answer 20

• Aerobic respiration

Question 21

Why does anaerobic respiration occur?

Answer 21

• when you do vigorous exercise and the body cannot supply enough oxygen to your muscles.

Question 22

Describe a positive pressure ventilator

Answer 22

• it pumps air into the lungs
• this expands the rib cage
• when it stops pumping, the ribcage relaxes and pushes air back out of the lungs.