[TRANSES] MODULE 3 UNIT 2 Flashcards
The main function of hemoglobin is (?).
to transport oxygen
Since oxygen is (?), it has to depend on
hemoglobin found in red blood cells for its transport to the
different organs and tissues of the human body.
non-water soluble
Hemoglobin increases (?) solubility in blood by about a
hundredfold.
O2
This means that without hemoglobin, in order to
provide sufficient (?), blood
would have to make a complete circuit through
the body in less than a second, instead of the
minute that it actually takes.
oxygen to the tissues
That would take a mighty powerful heart, which
in normal circumstances cannot be maintained
by the human heart leading to increased cardiac
output that may result to (?).
heart failure
During (?), each of the four heme iron atoms in a
hemoglobin molecule can reversibly bind one oxygen molecule.
oxygenation
Approximately (?) of oxygen is bound by each gram of
hemoglobin.
1.34 mL
Let’s follow the path of oxygen from the lungs to the peripheral
tissues.
Oxygen diffuses from the (1) of the lungs, little sacs at the end of the finely divided air passageways in the lung into the (2) of
the bloodstream and then into the (3), where it binds to hemoglobin.
- alveoli
- capillaries
- red blood cells
The concentration of oxygen is relatively high in the alveoli, about
(?) mmHg which means that Hb is virtually 100% saturated in the
lungs and all four heme molecules have an O2 molecule bound to
them.
100 mmHg
The concentration of oxygen is relatively high in the alveoli, about
100 mmHg which means that Hb is virtually (?) in the
lungs and all four heme molecules have an O2 molecule bound to
them.
100% saturated
The concentration of oxygen is relatively high in the alveoli, about
100 mmHg which means that Hb is virtually 100% saturated in the
lungs and all (?) have an O2 molecule bound to
them.
four heme molecules
The reference interval for arterial oxygen saturation is (?).
96% to 100%
The affinity of hemoglobin for oxygen relates to the partial
pressure of oxygen (PO2), often defined in terms of the amount of
oxygen needed to saturate 50% of hemoglobin, called the (?).
P50 value
The relationship is described by the (?) of hemoglobin, which plots the percent oxygen saturation of hemoglobin versus the PO2
oxygen dissociation curve
The curve is (?), which indicates low hemoglobin affinity for
oxygen at low oxygen tension and high affinity for oxygen at high
oxygen tension.
sigmoidal
Cooperation among hemoglobin subunits contributes to the (?).
shape of the curve
Hemoglobin that is completely (?) has little affinity for
oxygen.
deoxygenated
The secret to hemoglobin’s success as an oxygen delivery
molecule is the fact that it has (?) that communicate to
each other.
four subunits
In order to achieve [?] (an average of 1 O2 molecule per hemoglobin), the amount of O2 needs to be about 18 mm Hg.
25% saturation
In order to achieve 25% saturation (an average
of 1 O2 molecule per hemoglobin), the amount
of O2 needs to be about (?).
18 mm Hg
In order to achieve [?] (an average of 2 O2 molecules per hemoglobin), the amount of O2 needs to be about 27 mm Hg.
50% saturation
In order to achieve 50% saturation (an average
of 2 O2 molecules per hemoglobin), the amount
of O2 needs to be about (?).
27 mm Hg
Therefore, it is easier to bind the second molecule of O2 than the
first. This was illustrated by (?), Nobel Prize winners for Chemistry for their studies of the structures of hemoglobin and myoglobin.
Max Perutz and John Kendrew
Using (?), hemoglobin was found to have two
different forms or shapes.
X-ray diffraction
The (?) is dependent on the presence or
absence of oxygen.
conformation or shape
The experiments revealed that (?) has a relatively low attraction for oxygen, but when one molecule of oxygen binds to a heme group, the structure changes to the oxygenated form, which has a greater attraction for oxygen.
deoxyhemoglobin
Therefore, the (?) binds more easily, and the
third, and fourth even more easily.
second molecule of O2
The oxygen affinity of (?) is many times greater than
that of deoxy-hemoglobin.
oxy-hemoglobin
The oxygen dissociation curve illustrates the relationship between
(?).
yung graph is asa top second column HAHAHAHA
oxygen saturation of hemoglobin and the partial pressure of
oxygen
(?) is the partial pressure of oxygen (O2) needed for 50% O2 saturation of hemoglobin.
P50
↓ 2,3-bisphosphoglycerate (2,3-BPG) (e.g., multiple transfusion of stored blood)
In the Left-shifted (L): ↓ P50
↓ H+ ions (↑pH)
In the Left-shifted (L): ↓ P50
↓ (PCO2)
In the Left-shifted (L): ↓ P50
Hemoglobin F and hemoglobin variants
In the Left-shifted (L
o Hemoglobin F and hemoglobin variants
↑ oxygen affinity
In the Left-shifted (L)
o Hemoglobin F and hemoglobin variants
Alkalosis
In the Left-shifted (L)
↑ 2,3-BPG (e.g., in response to
hypoxic conditions such as in
high altitudes)
In the Right-shifted (R): ↑ P50
↑ H+ ions (↓ pH)
In the Right-shifted (R): ↑ P50
↑ PCO2, and/or temperature
In the Right-shifted (R): ↑ P50
o Pulmonary insufficiency
In the Right-shifted (R)
o Hemoglobin variants
↓ oxygen affinity
In the Right-shifted (R)
o Congestive heart failure
In the Right-shifted (R)
o Severe anemia
In the Right-shifted (R)
Factors that affect Hemoglobin affinity for Oxygen:
A patient with arterial and venous PO2 levels in the
reference intervals (80 to 100 mm Hg arterial and 30 to 50
mm Hg venous)
SHIFT TO THE LEFT
Factors that affect Hemoglobin affinity for Oxygen:
A patient with arterial and venous PO2 levels in the
reference intervals (80 to 100 mm Hg arterial and 30 to 50
mm Hg venous)
Partial pressure of oxygen
Factors that affect Hemoglobin affinity for Oxygen:
A patient with arterial and venous PO2 levels in the
reference intervals (80 to 100 mm Hg arterial and 30 to 50
mm Hg venous)
↑ percent oxygen saturation
Factors that affect Hemoglobin affinity for Oxygen:
A patient with arterial and venous PO2 levels in the
reference intervals (80 to 100 mm Hg arterial and 30 to 50
mm Hg venous)
↑ affinity for oxygen
↓ affinity for oxygen
↑ pCO2
↓ pH
↑ H+
SHIFT TO THE RIGHT
↓ affinity for oxygen
↑ pCO2
↓ pH
↑ H+
pH of blood
↓ affinity for oxygen
↑ pCO2
↓ pH
↑ H+
Bohr effect
↑ cellular respiration
↑ metabolic activity
↑ CO2
↓ O2
Strenuous physical activities