BIOL 253 Exam 3 UPDATED Exam
Questions and CORRECT Answers
Forms of O2 in blood - CORRECT ANSWER - 1. dissolved in plasma and erythrocyte
cytosol
2. reversibly combined with hemoglobin molecules in the erythrocytes
Hemoglobin - CORRECT ANSWER - protein made up of four subunits bound together
subunit consists of a heme and a polypeptide attached to the heme
one molecule can bind four O2 molecules
globin - CORRECT ANSWER - the four polypeptides of a hemoglobin molecule
Forms of Hemoglobin - CORRECT ANSWER - deoxyhemoglobin (Hb) and
oxyhemoglobin (HbO2)
percent hemoglobin saturation - CORRECT ANSWER - fraction of oxyhemoglobin
molecules relative to hemoglobin molecules present in a blood sample
%= (O2 bound to Hb/maximal capacity of Hb to bind O2) *100
oxygen carrying capacity - CORRECT ANSWER - the maximum amount of oxygen that
can be transported by hemoglobin
anemia - CORRECT ANSWER - significant decrease in hemoglobin in the blood
,oxygen-hemoglobin dissociation curve - CORRECT ANSWER - quantitative relationship
between blood Po2 and o2 with hemoglobin
what contributes to the Po2 of the blood - CORRECT ANSWER - dissolved oxygen, not
oxygen bound to hemoglobin
diffusion gradient of oxygen movement into the blood - CORRECT ANSWER - alveoli to
plasma to erythrocytes
diffusion gradient of oxygen in tissue capillaries - CORRECT ANSWER - plasma to
interstitial fluid to mitochondria of tissue cells
exercise effect on o2 - CORRECT ANSWER - exercising muscle consumes more O2
which lowers intracellular and interstitial Po2
this increases the blood-to-cell Po2 which increases the rate of oxygen diffusion from blood to
cell
decrease in erythrocyte Po2 causes additional dissociation of hemoglobin and oxygen
active hyperemia contributes to increased O2 supply
hemoglobin saturation - CORRECT ANSWER - percent of hemoglobin that has O2 or any
other gas bound to its iron moiety regardless of the red cell concentration (hematocrit) in the
blood
effect of decreased hematocrit - CORRECT ANSWER - hemoglobin can be 100%
saturated with o2 but the oxygen-carrying capacity of the blood will be decreased
factors that influence hemoglobin saturation - CORRECT ANSWER - 1. PCO2
2. Temperature (increase = decreased affinity for oxygen, curve to right)
, 3. H+ Concentration (increase = decreased affinity for oxygen, curve to right))
4. DPG/ BPG concentration (increase = decreased affinity for oxygen)
5. presence of hemoglobin found in fetal blood
fetal hemoglobin - CORRECT ANSWER - has a higher affinity for oxygen than adult
hemoglobin
allows adequate oxygen uptake in the placenta to supply the developing fetus
Carbon Monoxide (CO) - CORRECT ANSWER - A colorless, odorless gas that is
produced in small quantities by certain cells of the body and is believed to have physiologically
important functions
toxic at higher concentration; product of incomplete combustion of hydrocarbons
extremely high affinity for oxygen binding sites in hemoglobin; reduces amount of O2 that
combines with hemoglobin in pulmonary capillaries
carbaminohemoglobin - CORRECT ANSWER - formed when 25% to 30% of CO2
molecules react reversibly with the amino groups of hemoglobin
carbonic anhydrase - CORRECT ANSWER - enzyme that catalyzes the reaction between
carbon dioxide and water to form carbonic acid
present in erythrocytes but not in plasma
total-blood carbon dioxide - CORRECT ANSWER - sum total of dissolved carbon
dioxide, HCO3-, and carbon dioxide in carbaminohemoglobin
Questions and CORRECT Answers
Forms of O2 in blood - CORRECT ANSWER - 1. dissolved in plasma and erythrocyte
cytosol
2. reversibly combined with hemoglobin molecules in the erythrocytes
Hemoglobin - CORRECT ANSWER - protein made up of four subunits bound together
subunit consists of a heme and a polypeptide attached to the heme
one molecule can bind four O2 molecules
globin - CORRECT ANSWER - the four polypeptides of a hemoglobin molecule
Forms of Hemoglobin - CORRECT ANSWER - deoxyhemoglobin (Hb) and
oxyhemoglobin (HbO2)
percent hemoglobin saturation - CORRECT ANSWER - fraction of oxyhemoglobin
molecules relative to hemoglobin molecules present in a blood sample
%= (O2 bound to Hb/maximal capacity of Hb to bind O2) *100
oxygen carrying capacity - CORRECT ANSWER - the maximum amount of oxygen that
can be transported by hemoglobin
anemia - CORRECT ANSWER - significant decrease in hemoglobin in the blood
,oxygen-hemoglobin dissociation curve - CORRECT ANSWER - quantitative relationship
between blood Po2 and o2 with hemoglobin
what contributes to the Po2 of the blood - CORRECT ANSWER - dissolved oxygen, not
oxygen bound to hemoglobin
diffusion gradient of oxygen movement into the blood - CORRECT ANSWER - alveoli to
plasma to erythrocytes
diffusion gradient of oxygen in tissue capillaries - CORRECT ANSWER - plasma to
interstitial fluid to mitochondria of tissue cells
exercise effect on o2 - CORRECT ANSWER - exercising muscle consumes more O2
which lowers intracellular and interstitial Po2
this increases the blood-to-cell Po2 which increases the rate of oxygen diffusion from blood to
cell
decrease in erythrocyte Po2 causes additional dissociation of hemoglobin and oxygen
active hyperemia contributes to increased O2 supply
hemoglobin saturation - CORRECT ANSWER - percent of hemoglobin that has O2 or any
other gas bound to its iron moiety regardless of the red cell concentration (hematocrit) in the
blood
effect of decreased hematocrit - CORRECT ANSWER - hemoglobin can be 100%
saturated with o2 but the oxygen-carrying capacity of the blood will be decreased
factors that influence hemoglobin saturation - CORRECT ANSWER - 1. PCO2
2. Temperature (increase = decreased affinity for oxygen, curve to right)
, 3. H+ Concentration (increase = decreased affinity for oxygen, curve to right))
4. DPG/ BPG concentration (increase = decreased affinity for oxygen)
5. presence of hemoglobin found in fetal blood
fetal hemoglobin - CORRECT ANSWER - has a higher affinity for oxygen than adult
hemoglobin
allows adequate oxygen uptake in the placenta to supply the developing fetus
Carbon Monoxide (CO) - CORRECT ANSWER - A colorless, odorless gas that is
produced in small quantities by certain cells of the body and is believed to have physiologically
important functions
toxic at higher concentration; product of incomplete combustion of hydrocarbons
extremely high affinity for oxygen binding sites in hemoglobin; reduces amount of O2 that
combines with hemoglobin in pulmonary capillaries
carbaminohemoglobin - CORRECT ANSWER - formed when 25% to 30% of CO2
molecules react reversibly with the amino groups of hemoglobin
carbonic anhydrase - CORRECT ANSWER - enzyme that catalyzes the reaction between
carbon dioxide and water to form carbonic acid
present in erythrocytes but not in plasma
total-blood carbon dioxide - CORRECT ANSWER - sum total of dissolved carbon
dioxide, HCO3-, and carbon dioxide in carbaminohemoglobin
