mass transport

Question 1

what is oxygen association

Answer 1

the loading of oxygen into haemoglobin

Question 2

what is a high affinity for oxygen

Answer 2

more likely to bind to oxygen

Question 3

how many O2 molecules can bind to a haemoglobin molecule

Answer 3

four

Question 4

what type of protein is haemoglobin

Answer 4

quaternary protein

Question 5

describe the quaternary structure of haemoglobin

Answer 5

4 polypeptide chains, each associated with a haem group, near-spherical molecule

Question 6

what does an increase in CO2 produced do?

Answer 6

higher rate of respiration –> more CO2 produced by tissue –> lower pH (more negative) –> greater haemoglobin shape change –> oxygen dissociates more readily –> more oxygen available for respiration

Question 7

which blood vessel joins the right ventricle to the capillaries of the lungs

Answer 7

pulmonary artery

Question 8

which blood vessel carries oxygenated blood away from the heart

Answer 8

aorta

Question 9

which blood vessel carries deoxygenated blood away from the kidney

Answer 9

renal vein

Question 10

what is the first main blood vessel that an oxygen molecule reaches after being absorbed from an alveolus

Answer 10

aorta

Question 11

state two factors that make it more likely that an organism will have a circulatory pump such as the heart

Answer 11

high metabolic rate
small surface area to volume ratio

Question 12

state the main advantage of the double circulation found in mammals

Answer 12

high blood flow and pressure means that the blood can easily circulate the body

Question 13

what happens during atrial systole

Answer 13

the atria contract

Question 14

what happens during atrial diastole

Answer 14

the atria relax

Question 15

what happens during ventricular systole

Answer 15

the ventricles contract

Question 16

what happens during ventricular diastole

Answer 16

the ventricles relax

Question 17

define cardiac output

Answer 17

the volume of blood pumped by one ventricle of the heart in one minute (measured in dm3min-1)

Question 18

cardiac output calculation

Answer 18

cardiac output = heart rate x stroke volume

Question 19

when do the atrioventricular valves open

Answer 19

when the pressure of the atrium is higher than the ventricular pressure

Question 20

when do the atrioventricular valves close

Answer 20

when the pressure of the ventricle is higher than the atrial pressure

Question 21

when do the semilunar valves open

Answer 21

when the pressure of the ventricle is higher than the artery pressure

Question 22

when do the semilunar valves close

Answer 22

when the pressure of the artery is higher than the ventricular pressure

Question 23

name the layers of the blood vessels

Answer 23

lumen, endothelium, elastic layer, muscle layer, tough fibrous outer layer

Question 24

name the blood vessels

Answer 24

artery, arterioles, capillaries, veins

Question 25

what does the xylem transport

Answer 25

water and minerals

Question 26

what does the phloem transport

Answer 26

sugars and assimilates

Question 27

which cells are needed to produce an open stomata

Answer 27

guard cells

Question 28

what controls the volume of water lost via transpiration in plants

Answer 28

stomata opening and closing

Question 29

how does light intensity affect the rate of transpiration

Answer 29

it increases the rate of transpiration, light causes stomata to open leading to increased surface area for avaporation

Question 30

how does temperature affect the rate of transpiration

Answer 30

higher temperature causes water molecules to have more kinetic energy, therefore, more evaporation takes place, increasing the rate of transpiration

Question 31

what three things causes water to move up the xylem (cohesion tension theory)

Answer 31

cohesion, adhesion and root pressure

Question 32

describe the cell wall pathway for the movement of water across roots

Answer 32

movement of water along cell walls and through spaces between cells, pathway of least resistance, most water (90%) is absorbed this way

Question 33

describe the cytoplastic pathway for the movement of water across rootes

Answer 33

movement of water from cell to cell through plasmodesmata, pathway of resistance so less water is absorbed this way

Question 34

what direction does the xylem transport water and minerals

Answer 34

upwards

Question 35

what direction does the phloem transport sugars and assimilates

Answer 35

upwards and downwards

Question 36

where do the xylem transport water/minerals to and from

Answer 36

root hair cells to leaves/epidermis

Question 37

where do the phloem transport sugars/assimilates to and from

Answer 37

sources to sinks

Question 38

by which process does xylem transport water/minerals

Answer 38

transpiration

Question 39

by which process does phloem transport sugars/assimilates

Answer 39

translocation

Question 40

are xylem vessel calls alice or dead

Answer 40

dead

Question 41

are phloem vessel cells alive or dead

Answer 41

alive

Question 42

name the two monosaccharide components of sucrose

Answer 42

glucose and fructose

Question 43

name the two monosaccharide components of maltose

Answer 43

beta glucose and beta glucose

Question 44

name the two monosaccharide components of lactose

Answer 44

glucose and galactose

Question 45

name the reaction that forms disaccharide and the bond

Answer 45

condensation reaction and glycosidic bonds

Question 46

how do you test for a non-reducing sugar

Answer 46

1. add benedicts solution and boil in water bath for five minutes 2. if its a non-reducing sugar it will stay blue (negative result) 3. next step is to break the non-reducing sugar into a reducing sugar 4. add hydrochloric acid and boil in water bath for five minutes 5. add sodium bicarbonate 6. use universal indicator to see if it has been neutralised 7. repeat benedicts test, should now turn green/orange/red (positive result)

Question 47

what are the three stages of translocation

Answer 47

active loading, movement through the phloem, movement of assimilates into the sink

Question 48

what happens during active loading using sucrose as an example

Answer 48

1. hydrogen ions are pumped out of companion cells into surrounding mesophyll cells by active transport 2. a high concentration of hydrogen ions builds up in the mesophyll cells 3. hydrogen ion move back into the companion cells down a concentration gradient with a co-transport protein 4. sucrose is transported with the hydrogen ions into the companion cells by facilitated diffusion 5. a high concentration of sucrose builds up in the mesophyll cells 6. sucrose diffuses into the sieve tube elements

Question 49

what happens during movement through phloem using sucrose as an example

Answer 49

1. increase in concentration of sucrose in the sieve tube elements leads to a more negative water potential 2. water moves into the sieve tube elements by osmosis from surrounding cells such as xylem 3. turgor pressure in sieve tube elements increases causing movement of water and assimilates (such as sucrose) by mass flow from source to sink

Question 50

what happens during movement of assimilates into the sink using sucrose as an example

Answer 50

1. sucrose diffuses into the cells surrounding the sieve tube elements 2. these cells convert the sucrose into other substances, lowering the concentration of sucrose, creating a concentration gradient, causing more sucrose to diffuse out of the sieve tube elements 3. water potential inside sieve tube elements increases causing water to move out of the sieve tube elements into surrounding cells by osmosis 4. turgor pressure inside the sieve tube elements decreases, maintaining the mass flow inside the phloem