Respiration

Question 1

what is aerobic respiration?

Answer 1

• oxidation of glucose
• presence of oxygen
• large amount of energy released

Question 2

what is the chemical equation for aerobic respiration?

Answer 2

C6H12O6 + 6O2 —> large amounts of energy + 6CO2 + 6H2O

Question 3

what leads to anaerobic respiration in humans?

Answer 3

• muscles contract more vigorously
• increase in energy demand
• increased heart and breathing rate for greater rate of respiration
• increased oxygen uptake is unable to meet energy demands
• anaerobic respiration releases additional energy required for muscle contraction

Question 4

what is/are the waste product(s) of anaerobic respiration?

Answer 4

lactic acid

Question 5

what happens to lactic acid in muscles?

Answer 5

• converted to glucose then glycogen for storage in liver and muscles
• sent to the liver to be oxidized into water and carbon dioxide

Question 6

what is oxygen debt?

Answer 6

• additional oxygen required to oxidize lactic acid in the liver
• heart + breathing rate returns to normal after oxygen debt is paid (all lactic acid oxidized)

Question 7

what is the word equation for anaerobic respiration?

Answer 7

glucose —> small amount of energy + lactic acid

Question 8

what is the word equation for anaerobic respiration in yeast (alcoholic fermentation)?

Answer 8

glucose —> small amount of energy + ethanol + carbon dioxide

Question 9

how is the respiration rate measured?

Answer 9

respirometer

Question 10

what are the parts of the respiratory system?
(hint: 11)

Answer 10

• external nostril
• nasal passages
• pharynx
• larynx
• trachea
• bronchi
• bronchiole
• alveoli
• diaphragm
• internal intercostal muscles
• external intercostal muscles

Question 11

sequence of air passage

Answer 11

1. external nostril
2. nasal passages
3. pharynx
4. larynx
5. trachea
6. bronchi
7. bronchioles
8. alveoli

Question 12

function of the larynx

Answer 12

• contains vocal cords
• air passage for sound production

Question 13

features of the trachea

Answer 13

• C-shaped cartilages that supports the trachea
• C-shaped cartilages prevent the collapse of the airways

Question 14

function of the bronchi

Answer 14

air passage to the lungs

Question 15

what is the trachea and bronchi lined with?

Answer 15

• goblet cells to produce mucus to trap dust and bacteria
• ciliated cells to sweep mucus containing bacteria and dust to the pharynx to be swallowed

Question 16

function of the diaphragm

Answer 16

changes the volume of thoracic cavity for breathing

Question 17

what is the process of inhalation?

Answer 17

• diaphragm contracts and flattens
• external intercostal muscles contract
• internal intercostal muscles relax
• ribs move upwards and outwards
• volume of thoracic cavity increases
• air pressure in the lungs decreases
• atmospheric pressure is greater than air pressure in the lungs
• air rushes into the lungs

Question 18

what is the process of exhalation?

Answer 18

• diaphragm relaxes and arches upwards
• external intercostal muscles relax
• internal intercostal muscles contract
• ribs move downwards and inwards
• volume of thoracic cavity decreases
• lungs are compressed
• air pressure in the lungs increases
• atmospheric pressure is lower than the air pressure in the lungs
• air forced out of the lungs

Question 19

composition of inhaled air

Answer 19

• 78% nitrogen
• 0.03% carbon dioxide
• 21% oxygen

Question 20

composition of exhaled air

Answer 20

• 78% nitrogen
• 4% carbon dioxide
• 16% oxygen

Question 21

state two structures of the alveoli and their functions

Answer 21

• thin film of moisture on the inner surface of the alveoli - allow oxygen to dissolve in it
• well supplied by blood capillaries - to maintain a steep concentration gradient
• one cell thick epithelium - reduces distance of diffusion for a higher rate of diffusion of gases
• numerous alveoli in the lungs - for a greater surface area to volume ratio for efficient gaseous exchange

Question 22

how is the concentration gradient between alveolar air and blood maintained?

Answer 22

• continuous blood flow through the capillary
• breathing air in and out of the alveoli

Question 23

what does oxygen bind with?

Answer 23

oxygen binds with haemoglobin to form oxyhaemoglobin

Question 24

what catalyzes the formation of carbonic acid from carbon dioxide and water?

Answer 24

carbonic anhydrase in the red blood cells

Question 25

what does carbonic acid dissociate to?

Answer 25

hydrogen and hydrogencarbonate ions which diffuses out of the red blood cell and into the blood plasma

Question 26

what happens to carbon dioxide and water at the tissues

Answer 26

• diffuse into the red blood cells
• catalyzes into carbonic acid in the presence of carbonic anhydrase
• dissociates into hydrogen and hydrogencarbonate ions
• diffuse out of the red blood cells to blood plasma

Question 27

what happens to hydrogen and hydrogencarbonate ions at the lungs?

Answer 27

• diffuse into red blood cells
• converted to carbonic acid
• catalyzes into carbon dioxide and water in the presence of carbonic anhydrase
• diffuse out of the red blood cells, then blood capillaries, into the alveolus

Question 28

what are the symptoms of chronic bronchitis?
(hint: 7)

Answer 28

• paralyzed cilia
• inflammation of membrane in trachea and bronchi
• chronic coughing
• excessive production of mucus
• difficulty in breathing (narrowed airways)
• lungs are susceptible to infection
• may lead to emphysema and lung failure

Question 29

what is emphysema developed from?

Answer 29

chronic bronchitis

Question 30

what are the symptoms of emphysema?
(hint: 5)

Answer 30

• chronic coughing
• enlarged alveoli, leading to a reduced surface area
• lungs expand and lose elasticity
• great difficulty in breathing and strain on heart
• lung tissue damaged beyond repair

Question 31

what are the symptoms of lung cancer?
(hint: 4)

Answer 31

• uncontrolled growth of cells in the lungs that can spread which blocks bronchioles
• cancerous growth spreads to other parts of the body
• difficulty in breathing
• blood in sputum

Question 32

what are the causes of lung cancer, emphysema and chronic bronchitis?

Answer 32

• smoking
• frequent exposure to polluted air