B7 Mass transport

Question 1

where can you find high concentration of oxygen in the body

Answer 1

lungs

Question 2

where does haemoglobin load oxygen

Answer 2

at the lungs

Question 3

where is there a low concentration of oxygen

Answer 3

respiring tissues eg muscles

Question 4

where can you find a high concentration of carbon dioxide

Answer 4

respiring tissues eg muscles

Question 5

what does oxygen and haemoglobin make

Answer 5

oxyhaemoglobin

Question 6

where is there a low affinity for oxygen

Answer 6

respiring tissues eg muscles

Question 7

what happens to affinity of haemoglobin at low partial pressure

Answer 7

decreases

Question 8

what happens to affinity of oxygen as partial pressure increases

Answer 8

it also increases

Question 9

what is the effect of the Bohr shift on the oxygen dissociation graph

Answer 9

there is an increased rate of respiration so there is more carbon dioxide. more co2 lowers the Ph of the blood forming a carbonic acid. so haemoglobin oxygen

Question 10

what happens when the first molecule of oxygen binds to haemoglobin

Answer 10

causes a conformational change to the shape (tertiary structure). making it difficult for the 2,3 and 4th molecule to bind

Question 11

how does an atheroma form?

Answer 11

damage to endothelium of the artery makes the white blood cells and fatty acids from the blood clump together forming fatty streaks.
over time more WBC and FA and connective tissue build up and harden to form fibrous plaque also known as atheroma

Question 12

what does an atheroma do

Answer 12

blocks lumen of artery and restricts blood flow. this causes blood pressure to increase, can cause myocardial infraction.

Question 13

how is coronary heart disease caused

Answer 13

when coronary arteries have many atheroma restricting blood flow

Question 14

what are the risk factors of CVD

Answer 14

high blood cholesterol
bad diet (salt)
cigarette smoking
high blood pressure

Question 15

how does high blood cholesterol cause CVD

Answer 15

cholesterol is one of the main fatty deposits that forms atheroma which increases formation of blood clots and increases blood pressure. Blocking flow of blood to coronary arteries causing myocardial infraction.

Question 16

what is myocardial infraction

Answer 16

heart attack caused by coronary artery being completely blocked by blood clot.

Question 17

how does cigarette smoking cause CVD

Answer 17

Cigarette smoke contains nicotine and carbon monoxide.
nicotine increases blood pressure.
nicotine haemoglobin reduces the amount of o2 transported in the blood to muscles
muscles with no o2 = heart attack

Question 18

what are the chambers of the heart

Answer 18

right and left atriums
right and left ventricles

Question 19

which wall of the 4 chambers is thicker and why

Answer 19

ventricles have a thicker muscular wall because they have to pump blood around the body at higher pressure

Question 20

what is the function of the aorta

Answer 20

carries oxygenated blood from left atrium to the rest of the body

Question 21

what is the function of the pulmonary artery

Answer 21

carries deoxygenated blood to the lungs to get oxygenated

Question 22

what is the function of the vena cava

Answer 22

brings deoxygenated blood from respiring tissues eg muscles back to the right atrium

Question 23

what is the function of the pulmonary vein

Answer 23

brings oxygenated blood back from the lungs to the left atrium

Question 24

what are the main features of a transport system

Answer 24

good blood supply
closed system of tubular vessels

Question 25

what circulatory systems do fish and mammals have

Answer 25

fish have a single circulatory system mammals have a double circulatory system

Question 26

what does the fish's single circulatory system consist of

Answer 26

heart - gills - body - heart

Question 27

what does the mammal's double circulatory system consist of

Answer 27

heart - body - heart - lungs - heart

Question 28

why do mammals have a double circulatory system

Answer 28

allows separate flow of oxygenated and deoxygenated blood

Question 29

what are the 3 stages of the cardiac cycle

Answer 29

atrial systole ventricular systole ventricular diastole

Question 30

what happens in atrial systole in cardiac cycle

Answer 30

atria contract pushing blood into the ventricles ventricles contract AV valves are open Semi lunar valves are closed

Question 31

what happens in ventricular systole in cardiac cycle

Answer 31

ventricles contract pushing blood away from the heart through pulmonary arteries and aorta atria relax AV valves are closed Semi lunar valves are open

Question 32

what happens in diastole in cardiac cycle

Answer 32

atria are relaxed and fill with blood from vena cava and pulmonary veins ventricles are also relaxed AV valves are open Semi lunar valves are closed

Question 33

what is the function of xylem

Answer 33

transports water and minerals to the leaves

Question 34

features of xylem

Answer 34

made of dead cells thick cell wall flow is upward

Question 35

what are the stages of the transpiration stream

Answer 35

1 = h20 moves into roots from soil by osmosis 2 = h20 moves from roots to xylem vessels 3 = h20 moves from xylem vessels to leaves to replace h20 lost 4 = h20 evaporates from cell surfaces in leaves into air spaces 5 = water vapour diffuses out of the leaf through stomata

Question 36

what is the function of the waxy cuticle

Answer 36

reduces h20 loss

Question 37

what is the function of guard cells

Answer 37

open+close stomata to regulate transpiration

Question 38

what are the two pathways for cells

Answer 38

apoplastic pathway = through cell wall symplastic pathway = through cytoplasm

Question 39

what is the transpirational pull

Answer 39

column of h20 is continuesly pulled up xylem as a result of transpiration

Question 40

evidence to support the cohesion tension theory

Answer 40

diameter of trunks daytime = more light = more transpiration nightime = less light = less transpiration if air enters xylem it can no longer draw up h20

Question 41

what is the function of phloem

Answer 41

transports organic molecules and mineral ions

Question 42

features of phloem

Answer 42

made of living cells flow is up and down has sources and sinks

Question 43

what do companion cells do

Answer 43

control transport of sugars

Question 44

what do sieve tubes do

Answer 44

allow flow of sap have no organelles to maximise space