Respiratory System 4

Question 1

what are the two ways that oxygen is transported in the blood

Answer 1

dissolved in blood plasma and chemically bound to hemoglobin

Question 2

define hemoglobin

Answer 2

protein contained in the red blood cells

Question 3

how many molecules of oxygen can a molecule of hemoglobin carry

Answer 3

4, one on each heme

Question 4

what is a fully saturated hemoglobin

Answer 4

all four heme groups bound to oxygen

Question 5

what is a partially saturated hemoglobin

Answer 5

1,2, or 3 oxygen molecules are bound to a hemoglobin molecule

Question 6

explain loading of O2 onto hemoglobin

Answer 6

occurs in the alveolar capillaries
oxygen binds to heme to form oxyhemoglobin (HbO2)

Question 7

explain unloading of O2 from hemoglobin

Answer 7

occurs in the tissues
oxygens unbinds from hemoglobin to form deoxyhemoglobin and oxygen

Question 8

what determines the direction of the hemoglobin reaction

Answer 8

partial pressure of oxygen in the blood and the affinity of hemoglobin and O2

Question 9

define the cooperative binding effect

Answer 9

each O2 that binds causes a conformational change in hemoglobin making it easier for next O2 to bind
produces a sigmoidal (S-shaped) curve

Question 10

explain the oxygen-hemoglobin saturation curve

Answer 10

initial curve is steep because of cooperative binding effect
as PO2 goes up, saturation goes up (happens in the alveoli)
as PO2 goes down, saturation goes down because it is being offloaded to go to the tissues

Question 11

define oxygen reserve

Answer 11

oxygen bound to hemoglobin after passing through the systemic circulation

Question 12

what are the 5 factors that affect hemoglobin’s binding and release of oxygen

Answer 12

PO2
pH
concentration of CO2
temperature
2,3-biphosphogylcerate (2,3-DPG)

Question 13

explain how PO2 affects hemoglobin’s binding and release of oxygen

Answer 13

as PO2 goes up, we have more binding of O2 to hemoglobin
as PO2 goes down, we have more releasing of O2 from hemoglobin

Question 14

explain how pH affects hemoglobin’s binding and release of oxygen

Answer 14

as pH goes down, H+ ions increase which decrease the affinity of oxygen to bind to hemoglobin
as pH goes up, H+ ions decrease which promotes the binding of oxygen to hemoglobin

Question 15

explain how concentration of CO2 affects hemoglobin’s binding and release of oxygen

Answer 15

CO2 concentrations and saturation are inversely related
when CO2 concentrations increase, O2 is released from hemoglobin
when CO2 concentrations decrease, O2 is bound to hemoglobin

Question 16

explain how temperature affects hemoglobin’s binding and release of oxygen

Answer 16

temperature and saturation are inversely related
as temperature increases, hemoglobin will release oxygen
as temperature decreases, hemoglobin will bind to oxygen

Question 17

explain how 2,3-biphosphoglycerate (2,3-DPG) affects hemoglobin’s binding and release of oxygen

Answer 17

inversely related
as 2,3-DPG levels goes up, oxygen will be released from hemoglobin
as 2,3-DPG levels go down, oxygen will bind to hemoglobin

Question 18

what does a right shift in a oxygen-hemoglobin saturation curve mean and what can cause it

Answer 18

Bohr effect: means that the % of oxygen saturation goes down
PO2 down
pH down; H+ up
concentration of CO2 up
temperature up
2,3-DGP up

Question 19

what does a left shift in a oxygen-hemoglobin saturation curve mean and what can cause it

Answer 19

Haldane effect: increase oxygen binding to hemoglobin
PO2 up
pH up; H+ down
concentration of CO2 down
temperature down
2,3-DGP down

Question 20

how does altitude affect oxygen-hemoglobin saturation

Answer 20

as we go up in altitude, PO2 in atmosphere goes down which means our oxygen saturation also goes down

Question 21

how does a pulse oximeter measure oxygen in the blood

Answer 21

goes on finger
special light passes through your skin into your blood
sensor measures the amount of light and % of red blood cells that are full of oxygen
determines amount of deoxyhemoglobin vs oxyhemoglobin
usually around 95%

Question 22

what are the three ways in which carbon dioxide is transported

Answer 22

as CO2 dissolved in plasma
attached to amine group of the globin portion of hemoglobin
as bicarbonate dissolved in plasma

Question 23

what is the equation for CO2 attaching to amine group of hemoglobin

Answer 23

CO2 + Hb <–> HbCO2 (carbaminohemoglobin)

Question 24

what are the two ways in which CO2 can be transported as bicarbonate dissolved in plasma

Answer 24

systemic capillaries and pulmonary capillaries

Question 25

explain how CO2 is transported as a bicarbonate dissolved in the blood plasma at the systemic capillaries

Answer 25

CO2 diffuses into red blood cell and combines with H2O to form carbonic acid - catalyzed by carbonic anhydrase
carbonic acid dissociates into bicarbonate and hydrogen ion
bicarbonate diffuses into plasma and chloride moves into red blood cell (chloride shift)

Question 26

explain how CO2 is transported as a bicarbonate dissolved in the blood plasma at the pulmonary capillaries

Answer 26

bicarbonate moves into the red blood cell, chloride moves out
bicarbonate combines with H+ to form carbonic acid
carbonic acid dissociates into CO2 and water (catalyzed by carbonic anhydrase)
CO2 diffuses out of red blood cell and into alveoli to be breathed out