respiratory part 3

Question 1

metalloproteins

Answer 1

respiratory pigments

• proteins containing metal ions
• reversibly bind to oxygen
• increase oxygen carrying capacity

Question 2

3 main types of respiratory pigments

Answer 2

1. hemoglobins
2. hemocyanins
3. hemerythrins

Question 3

hemeoglobin characteristics

Answer 3

vertebrates, nematods, some annelids/crustaceans
global protein bound to heme molecule
contains 4 iron groups (heme) 
within blood cells
appears red when oxygenated
2b a 2 b subunits (tetramer)

Question 4

what is myoglobin

Answer 4

a type of hemoglobin found in the muscles

Question 5

hemocyanin characteristics

Answer 5

arthropods and molluscs 
each protein contains two coppers which bind to one oxygen
dissolved in hemolymph
appears blue when oxygenated 
large multisubunit protein

Question 6

hemerythrin characteristics

Answer 6

invertebrates 
contains 2 iron bound to one subunit
trimeric/octomeric 
found inside coelomic cells
appears pink when oxygenated

Question 7

how does the relationship of Po2 affect pigment molecules

Answer 7

as Po2 increases, more pigment molecules bind oxygen

P50= point of Po2 at which pigment is 50% saturated

Question 8

shape of myoglobin oxygen equilibrium curve

Answer 8

hyperbolic

- oxygen binds independently

Question 9

shape of hemoglobin curve

Answer 9

sigmoidal

• each oxygen binds cooperatively
• hemoglobin has a higher affinity for oxygen as more heme groups bind

Question 10

what is the Bohr effect

Answer 10

decrease in pH or increase in Pco2 reduces oxygen affinity
p50 is increased
facilitates oxygen transport to active tissues and oxygen binding at respiratory surfaces

Question 11

root effect

Answer 11

reduction in oxygen carrying capacity

doesn’t reach same plateau

Question 12

temperature affect oxygen capacity

Answer 12

higher temperatures decrease oxygen affinity
P50 is increased
promotes oxygen delivery to warm muscles

Question 13

organic modulators affect on oxygen affinity

Answer 13

2,3-DPG
increase in modulators decrease oxygen affinity
helps oxygen unloading

Question 14

factors that decrease oxygen affinity

Answer 14

high temperature
high concentration of organic modulators
low pH
high Co2

Question 15

what are the three ways carbon dioxide is transported

Answer 15

1. small amounts transported through plasma
2. some CO2 binds to proteins
3. most CO2 transported as bicarbonate

Question 16

what is carbaminohemoglobin

Answer 16

protein that binds to CO2

Question 17

what catalyzes the formation of HCO3

Answer 17

carbonic anhydrase
located in RBCs
HCO3 is exchanged for Cl in the plasma

Question 18

what is the Haldane effect

Answer 18

deoxygenated blood can carry more CO2 than oxygenated

Question 19

how is PCo2 and pH related to HCO3 concentration

Answer 19

as PCO2 increases, HCO3 increases, and pH drops

as PCO2 decreases, HCO3 decreases and pH rises

Question 20

how is PCO2 related to ventilation?

Answer 20

hyper ventilation - PCO2 decreases

hypoventilation - PCO2 increases

Question 21

how is ventilation regulated

Answer 21

• chemoreceptors detect changes in CO2 (air) and O2 (water) modulates –>
• rhythmic firing of central pattern generators within the medulla initiate ventilatory movements