respiration part 3

Question 1

Less than ____% of the oxygen in the blood is dissolved

Answer 1

2%

Question 2

T/F: oxygen is relatively insoluble in the blood

Answer 2

true

Question 3

we must rely on O2 bound to hemoglobin to carry ____% of the total O2 in the blood

Answer 3

98%

Question 4

Hemoglobin is a respiratory _______

Answer 4

pigment

Question 5

hemoglobin is the predominant protein in what cell type

Answer 5

erythrocytes

Question 6

describe the structure of hemoglobin:

Answer 6

tetrameric molecule –

4 protein subunits, each with a heme group that includes 1 iron atom that can reversibly bind O2

Question 7

Total O2 in blood is a function of what?

Answer 7

PO2 and amount of Hb in blood

Question 8

Binding of O2 to Hb changes the __________ of the molecule

Answer 8

conformation

Question 9

the Plateau region of the Hb saturation curve is where the ________ phase occurs

Answer 9

loading

Question 10

the Steep region of the Hb saturation curve is where the _______ phase

Answer 10

unloading

Question 11

______ is the PO2 at which ½ of Hb is saturated

Answer 11

P50

50% saturation point

Question 12

oxygen delivery to tissues depends on what?

Answer 12

dissolved oxygen

Question 13

only _______ oxygen can diffuse into tissues

Answer 13

dissolved

Question 14

T/F: O2 bound to Hb can not diffuse into tissues

Answer 14

true

Question 15

In the alveoli, O2 must diffuse across respiratory surface into ________

Answer 15

plasma

Question 16

what maintains the P02 gradient in the alveoli and pulmonary blood?

Answer 16

Hb uptake of O2 maintains PO2 gradient

Question 17

how would a increased Hb affinity for O2 affect the Hb disassociation curve?

Answer 17

shift curve to the left

• makes it harder for Hb to release its bound oxygen

Question 18

how would a decreased Hb affinity for O2 affect the Hb disassociation curve?

Answer 18

shifts curve to the right

• causes Hb to release its bound oxygen easier

Question 19

what metabolic factors will decrease Hemoglobins affinity for Oxygen?

Answer 19

increased Temperature

increased CO2 (Bohr effect)

increased H+

increased 2,3 diphosphoglycerate

Question 20

DPG (2,3 diphosphoglycerate) binds to ___________ hemoglobin better than it does to _________ hemoglobin

Answer 20

deoxygenated hemoglobin better than it does to oxygenated hemoglobin

• net effect: shifts disassociation curve to the RIGHT

Question 21

how does anemia effect oxygen transport?

Answer 21

does not change arterial PO2 or Hb saturation

but TOTAL O2 content is reduced

Question 22

how does carbon monoxide reduce oxygen transport?

Answer 22

CO replaces O2 on Hb

Question 23

Hb affinity for CO is _____ times greater than for O2

Answer 23

200X

Question 24

what are the 3 ways CO2 is transported in the blood? which form accounts for the largest movement?

Answer 24

dissolved (7%)

bound to Hb (~23%)

**as HCO3- (70%)**

Question 25

T/F: CO2 will directly compete with O2 for binding sites on hemoglobin

Answer 25

FALSE CO2 has no direct competition for O2 binding sites

Question 26

what causes an increase in hemoglobins affinity for CO2?

Answer 26

increased partial pressure of CO2 (increased Pco2)

Question 27

Bicarbonate is formed in __________ but transported in the ______

Answer 27

formed in erythrocytes transported in the plasma

Question 28

what is the net result of the CO2 to HCO3- reaction?

Answer 28

Reaction acidifies the plasma

Question 29

the enzyme ______________ will convert CO2 and H2O into carbonic acid

Answer 29

carbonic anhydrase

Question 30

the Carbonic acid reaction reverses in the ________

Answer 30

lung

Question 31

H+ binds to _________ residues on Hb

Answer 31

histidine

Question 32

histadines affinity for H+ depends on what?

Answer 32

PO2

Question 33

____________ hemoglobin has a higher affinity for H+

Answer 33

deoxygenated

Question 34

Based on how Hemoglobin binds to H+, hypoventilation would cause ___________

Answer 34

causes respiratory acidosis

Question 35

Based on how Hemoglobin binds to H+, hyperventilation would cause ___________

Answer 35

causes respiratory alkalosis