respiration

Question 1

respiration D

Answer 1

oxidation of food molecules to release energy

Question 2

aerobic resp D

Answer 2

oxidation of food molecules in the presence of oxygen to release of a relatively large amt of energy

Question 3

anerobic resp D

Answer 3

oxidation of food molecules wihtout oxygen to release of a relatively small amt of energy

Question 4

where does aerobic resp occur?

Answer 4

mitochondria of cells
(enzymatic rxn)

Question 5

anaerobic resp during exercise

Answer 5

-muscles contract vigorously –> high energy demand
-(rate of breathing and heart rate increases so) rate of respiration increases
-rate of aerobic resp cannot increase any further and energy demand continues to increase
-anerobic resp occurs to provide additional energy required

Question 6

after exerise:

Answer 6

accumulation of lactic acid that is removed in liver
-heart rate remains high
-rate and depth of breathing remains high (lactic acid transported faster to liver)

Question 7

nostril F

Answer 7

hair and mucous layer: trap dust and foreign particles

Question 8

pharynx F

Answer 8

throat area (openings to trachea and oesophagus)

Question 9

larynx F
(vocal cords)

Answer 9

cartilaginous structure

Question 10

trachea F
(windpipe)

Answer 10

C-shaped rings of cartilage
-prevents collapse
-keeps airways open

Question 11

epithelium of airways (trachea and bronchus)

Answer 11

goblet cells and cililated cells

Question 12

goblet cells

Answer 12

produce mucus that trap dust and bacteria

Question 13

cilia

Answer 13

sweep mucus up bronchi and trachea into larynx

Question 14

properties of alveoli (5)

Answer 14

1. numerous alveoli
2. many blood capillaries
3. one-cell thick
4. thin film of water
5. maintenance of steep concentration gradient
   –> increase rate of diffusion of gases between alveoli and blood capillaries

Question 15

one-cell thick

Answer 15

short distance for quick diffusion of gases

Question 16

thin film of water

Answer 16

gases dissolve and diffuse easily into blood

Question 17

maintenance of steep conc gradient btwn alveoli and blood capillaries

Answer 17

-blood constantly flowing: keep conc of O2 low and CO2 high in blood capillaries
-constant breathing: conc of O2 high and CO2 low in alveoli space

Question 18

pulmonary arteriole

Answer 18

deoxygenated blood from heart

Question 19

pulmonary venule

Answer 19

oxygenated blood going to the heart

Question 20

process of O2 diffusion (at alveoli)

Answer 20

O2 molecules diffuse from alveolar space into RBCs in blood capillaries
(oxygenated carried towards left atrium by pulmonary vein)

Question 21

o2 diffusion at tissues

Answer 21

simple diffusion of o2 molecules from RBCs (unbind with haemoglobin) into body cells

Question 22

CO2 diffusion

Answer 22

CO2 molecules diffuse from blood in capillaries into alveoli

Question 23

exhalation

Answer 23

1. diaphragm relaxes, arches up
2. external intercostal muscles relax, internal intercostal muscles contract
   + rib cage: downwards and inwards
3. thoracic volume decreases
4. pressure in thoracic cavity increases above atmospheric pressure, lungs are compressed, air is forced out of lungs

Question 24

inhalation

Answer 24

1. diaphragm contracts, flattens down
2. external intercostal muscles contract, internal intercostal muscles relax
   + rib cage: upwards and outwards
3. thoracic volume increases
4. pressure in thoracic cavity decreases below atmospheric pressure, air is forced into lungs

Question 25

carbonic anhydrase

Answer 25

enzyme found in RBCs that catalyses conversion of carbon dioxide and water into carbonic acid (or vice versa: reversible rxn)

Question 26

at tissues (body cells)

Answer 26

-simple diffusion of co2 molecules from body cells into blood -co2 + h2o converted into carbonic acid (in RBCs) catalysed by carbonic anhydrase -CA dissociates to form bicarbonate and hydrogen ions (in blood plasma) --> bc of high conc of co2 in body cells

Question 27

at lungs

Answer 27

-bicarbonate and hydrogen ions readily react to form carbonic acid -CA converted to co2 & h2O, catalysed by carbonic anhydrase (in RBCs) -co2 molecules diffuse from RBC to blood plasma into alveoli to be removed via exhalation --> bc of low conc of co2 in lungs

Question 28

tobacco smoke components (3)

Answer 28

-nicotine -tar -CO

Question 29

nicotine effects

Answer 29

-increases risk of blood clotting, higher risk of coronary heart disease

Question 30

tar effects

Answer 30

-carcinogens -paralyses cilia lining airways: dust particles trapped in mucus lining cannot be removed --> higher risk of bronchitis & emphysema

Question 31

CO effects

Answer 31

binds tightly with haemoglobin in RBCs to form carboxyhaemoglobin -less haemoglobin available to bind with co2 --> reduced o2 transport around body

Question 32

emphysema

Answer 32

-walls btwn alveoli break down due to persistent violent coughing -total SA for GE decreases --> slower rate of diffusion of o2 into blood --> difficulty breathing

Question 33

chronic bronchitis

Answer 33

-tar coats cilia, becomes paralysed -excessive mucus secreted by goblet cells -trapped dust and bacteria stay in respiratory tract --> bacteria grow and multiply -persistent coughing --> airways become inflamed