BIO 1500 (BUSH MIZZOU) EXAM 5 | THE SMART WAY TO
PASS | REAL TESTS, REAL RESULTS!
- When O2 is binding to Hb, it first has a small affinity, but as more O2 binds, the affinity
increases. (No O2=bent/tense--O2=flat/relaxed) - Answer: connect molecular changes
during O2 binding to cooperative O2 binding properties
Of Hb
- The curve shift to the left for a higher affinity and right shift for in the body for decreased
affinity. The higher PO2 in the lungs and the lower in the body - Answer: relate the O2-Hb
dissociation curve to the partial O2 pressure in lung and body and
Explain the advantage of its sigmoidal shape.
- In the lung close to 100% for wide range of PO2
- In the body: steep part of sigmoid (big change when PO2 drops)
- At normal body PO2 hemoglobin keeps 70-80% of oxygen - Answer: Explain how the O2
affinity of Hb decreases in the body, incl. Which factors
Contribute to this decrease and how this facilitates the release of O2 in the body.
- higher affinity (lower temp, lower PCO2, higher ph, lower 2,3-BPG). When the O2 binds the
heme group is pulled towards ring, changing the structure. Charged/polar attach to
charged aa outside of subunits - Answer: . Summarize how ph, PCO2, temperature, and
2,3-BPG change the tertiary and
Quaternary structure of Hb and thus its O2 affinity.
- above 6000 m, PO2 is too low to efficiently bind to O2 in the lungs to allow sustained
work. Curve can't reach 100% bc there isn't enough PO2 - Answer: explain why human Hb
does not work sufficiently at high altitude, by relating PO2 at
Low and high altitude to the O2 Hb dissociation curve.
APPHIA – Crafted with Care and Precision for Academic Excellence. 1
, - Bird lungs are more complicated--the site of gas exchange in birds is parabronchi, and
alveoli in humans. Birds have a one directional flow of air and little residual volume -
Answer: explain how the bird respiratory system differs from that of mammals
- the air sacs "store" fresh and used air. They expand and contract. Keeps continuous fresh
air - Answer: explain the function of the air sacs and how the airflow in birds directs oxygen-
rich
Air through the lungs at all stages of respiration
- there is less mixing of fresh and used air - Answer: explain the advantage of unidirectional
airflow.
- the O2 is less at higher altitudes and low-alt birds use proline leucine, which has lower
affinity. Low alt birds cannot sufficiently use oxygen. Oxygen loading at high alt. Is bad bc
there's less O2 available - Answer: explain why the high efficiency respiratory system of
birds does not work sufficiently
Well at high altitude.
- the high alt. Birds have a shift to the left for a higher affinity. It releases and grabs O2 more
readily. Higher % bound. The higher affinities have lower PO2. - Answer: interpret the O2-Hb
dissociation curves of normal (low altitude) and high-altitude
Birds (e.g bar-headed geese) with respect to the PO2 available to them.
T - Answer: A binds to
G - Answer: C binds to
U - Answer: in RNA T turns into
APPHIA – Crafted with Care and Precision for Academic Excellence. 2
PASS | REAL TESTS, REAL RESULTS!
- When O2 is binding to Hb, it first has a small affinity, but as more O2 binds, the affinity
increases. (No O2=bent/tense--O2=flat/relaxed) - Answer: connect molecular changes
during O2 binding to cooperative O2 binding properties
Of Hb
- The curve shift to the left for a higher affinity and right shift for in the body for decreased
affinity. The higher PO2 in the lungs and the lower in the body - Answer: relate the O2-Hb
dissociation curve to the partial O2 pressure in lung and body and
Explain the advantage of its sigmoidal shape.
- In the lung close to 100% for wide range of PO2
- In the body: steep part of sigmoid (big change when PO2 drops)
- At normal body PO2 hemoglobin keeps 70-80% of oxygen - Answer: Explain how the O2
affinity of Hb decreases in the body, incl. Which factors
Contribute to this decrease and how this facilitates the release of O2 in the body.
- higher affinity (lower temp, lower PCO2, higher ph, lower 2,3-BPG). When the O2 binds the
heme group is pulled towards ring, changing the structure. Charged/polar attach to
charged aa outside of subunits - Answer: . Summarize how ph, PCO2, temperature, and
2,3-BPG change the tertiary and
Quaternary structure of Hb and thus its O2 affinity.
- above 6000 m, PO2 is too low to efficiently bind to O2 in the lungs to allow sustained
work. Curve can't reach 100% bc there isn't enough PO2 - Answer: explain why human Hb
does not work sufficiently at high altitude, by relating PO2 at
Low and high altitude to the O2 Hb dissociation curve.
APPHIA – Crafted with Care and Precision for Academic Excellence. 1
, - Bird lungs are more complicated--the site of gas exchange in birds is parabronchi, and
alveoli in humans. Birds have a one directional flow of air and little residual volume -
Answer: explain how the bird respiratory system differs from that of mammals
- the air sacs "store" fresh and used air. They expand and contract. Keeps continuous fresh
air - Answer: explain the function of the air sacs and how the airflow in birds directs oxygen-
rich
Air through the lungs at all stages of respiration
- there is less mixing of fresh and used air - Answer: explain the advantage of unidirectional
airflow.
- the O2 is less at higher altitudes and low-alt birds use proline leucine, which has lower
affinity. Low alt birds cannot sufficiently use oxygen. Oxygen loading at high alt. Is bad bc
there's less O2 available - Answer: explain why the high efficiency respiratory system of
birds does not work sufficiently
Well at high altitude.
- the high alt. Birds have a shift to the left for a higher affinity. It releases and grabs O2 more
readily. Higher % bound. The higher affinities have lower PO2. - Answer: interpret the O2-Hb
dissociation curves of normal (low altitude) and high-altitude
Birds (e.g bar-headed geese) with respect to the PO2 available to them.
T - Answer: A binds to
G - Answer: C binds to
U - Answer: in RNA T turns into
APPHIA – Crafted with Care and Precision for Academic Excellence. 2
