oxygen and carbon dioxide transport

Question 1

how does haemoglobin function as a useful respiratory pigment

Answer 1

picks up O2 in areas w/high ppO and releases O2 where there is a low ppO

Question 2

what type of protien is hamoglobin

Answer 2

globular, conjugated

Question 3

state the prosthetic group in haemoglobin

Answer 3

haem group which is an iron(II) ion

Question 4

how many haem groups does Hb have

Answer 4

4

Question 5

how many O2 molecules can Hb carry

Answer 5

4

Question 6

where do O2 molecules bind to in Hb

Answer 6

haem groups

Question 7

what is formed when Hb and O2 combine

Answer 7

oxyhaemoglobin

Question 8

what is the equation for the formation of oxyhaemoglobin

Answer 8

Hb+4O2->HbO8

reversible

Question 9

what is meant by the terms loading and unloading

Answer 9

Hb binding with ox

Hb relasing ox

Question 10

what does Hb’s affinity depend

Answer 10

p(O2)

Question 11

what does Hb’s affinity depend on

Answer 11

p(O2)

Question 12

effect of ox conc on affinity

Answer 12

high ox conc= high p(O2)=high afinity

low ox conc= low ppO= low affinity

Question 13

when the frst ox binds does it make it easier/ harder for other ox to bind

Answer 13

easier

Question 14

why is it difficult for ox to load onto haem groups at low ppO

Answer 14

polypeptide chains tightly bound

Question 15

when the frst ox binds does it make it easier/ harder for other ox to bind

Answer 15

easier- positve cooperativity

Question 16

what causes the ox diss curve to rise steeply

Answer 16

after 1 ox binds polypeptide chain opens exposing other 3 groups

Question 17

why does the ox dis curve level of at high ppO

Answer 17

Hb is saturated

Question 18

what has a higher aff for ox fetal/ adult Hb

Answer 18

fetal

Question 19

importance of fetal Hb having a higher ox aff

Answer 19

fetus needs ox from mother’s blood, ppO low in placenta, adult Hb needs to unload and fetal Hb needs to load, maintains conc grad across placenta

Question 20

where is the postioning of fetal cuvre cmpared to the adult cruve

Answer 20

to the left

Question 21

biconcave shape

Answer 21

larger surface area for gaseous exchange, pass through narrow capillaries

Question 22

why do erythroctes have a limited life

Answer 22

no nucleus/ mitochindra

Question 23

what is Hb composed of

Answer 23

4 peptide chains

Question 24

where are there relatively low ox levels

Answer 24

capillaries in the lungs

Question 25

what is there bw inside of Hb and air in alveoli

Answer 25

steep conc gradient- ox

Question 26

how is a steep concentarion gradent maintained in erythrocyte

Answer 26

ox bound to Hb so free ox conc in erythrocyte stays low

Question 27

what is rel ox con in cyto of body cells compared to in RBCs

Answer 27

lower in body cells

Question 28

describe unloading

Answer 28

ox moves out of RBC down conc grad, after 1 released Hb changes shape so easier for other ox to be released

Question 29

what are axis of ox diss curve

Answer 29

% saturation of Hb in blood plotted against ppO

Question 30

what does ox diss graph show

Answer 30

% saturation of Hb in blood plotted against ppO

Question 31

where is myoglobin found

Answer 31

muscles

Question 32

explain diff bw Hb and myoglobin

Answer 32

myoglobin has a much higher aff for ox so muscles can take ox from Hb in blood, enabling muscles to get extra ox when contracting during exercise

Question 33

when is myoglobin used

Answer 33

when the amount of ox falls

Question 34

what happens to the overall pa of air as altitude increases

Answer 34

decreases, proportions stay the same

Question 35

what is meant by ppO

Answer 35

rel conc of ox compared to other gases

Question 36

why does a little change in ppO make a sig diff to saturation of Hb w/O2

Answer 36

once first mol att the change in shape means other ox mols added rapidly

Question 37

where does rapid loading occur

Answer 37

lungs- bc low ppO

Question 38

what happens when resp cells a a small drop in ox levels. how is the eff enhanced

Answer 38

ox rel rapidly from Hb to diffuse into cells | enhanced by rel low pH in tissues comp to lungs

Question 39

importance of Bohr effect in lungs

Answer 39

rel low ppCO2 so ox binds to Hb easily

Question 40

what happens to curve when co2 conc inc

Answer 40

shifts right- Bohr shift

Question 41

imp of bohr effect in active tissues

Answer 41

have high ppCO2 sp Hb gives up its ox more easily

Question 42

what would be the case if fetal and adult Hb had the same afff for ox

Answer 42

little or no ox tranfered to fetal blood as no conc grad established

Question 43

how is co2 transported from tissues to lungs

Answer 43

plasma carbominoHb (mostly) hydrogen carbonate ions in cyto of RBCs

Question 44

how is carbominhaemoglobin formed

Answer 44

co2 comines w/ a.a groups in pp chains of Hb

Question 45

co2 reacts slowly with water to form

Answer 45

carbonic acid-H2CO-

Question 46

what does carbonic acid dissociate to form

Answer 46

hydrogen ion and and hydrogen carbonate ion- HCO3-

Question 47

name and functions of enzyme inv in formation of carbonic acid

Answer 47

carbonic anhydrase | catalyses the rversible reaction bw co2 and water

Question 48

what type of reation is the formation and diss of carbonic acid

Answer 48

reversible

Question 49

descirbe process of hydrogen carbonate leaving the Hb

Answer 49

diffuses out of RBC, down conc grad

Question 50

describe chloride shift

Answer 50

as negative HCO3- diff out, Cl- diff into RBC

Question 51

purpose of chloride shift

Answer 51

to maintain the electrical balance of the RBC

Question 52

what does removing and converting co2 into HCO3-s do

Answer 52

maintains steep conc grad for co2 to diffuse from the respiring tissues into RBCs

Question 53

describe what happens to carbonic acid when blood reaches lungs tissue

Answer 53

carbonic acid catalyses the reverse reaction- b.down c.acid into co2 and water

Question 54

describe what happens to cl- when blood reaches lungs

Answer 54

diff out of RBC down electrochemical gradient

Question 55

describe what happens to HCO3- when blood reaches lungs

Answer 55

diff back into RBC and react w/ H+ to form more c.acid

Question 56

descibe the role of Hb when blood reaches lungs

Answer 56

acts as a buffer- prevents changes in pH by accepting free H+ in a reversible reaction to form haemoglobinic acid

Question 57

how is haemoglobinic acid formed

Answer 57

when Hb accepts free H+s

Question 58

how is the absence of nucei in mature RBCs an adaptation

Answer 58

allows more room for maximum amount of Hb

Question 59

how is the presence of Hb in RBCs an adaptation

Answer 59

able to carry oxygen

Question 60

how is the enzyme carbonic anhydrase an adaptation of RBCs

Answer 60

inv in carriage of co2 in blood

Question 61

show diff in myoglobin and Hb curve

Answer 61

.

Question 62

show diff bw fetal and adult Hb curves

Answer 62

.

Question 63

use flow chart to summarise how co2 prod in cells is carried to lungs in RBCs

Answer 63

clearly shw main stages of co2 transport | x incl plasma transport as spec states RBCs