Respiratory pigments bind and
transport gases
42.7
Respiratory Pigments
• Proteins involved in respiration. They are in
charge of transporting oxygen rather than
allowing the oxygen to be dissolved the
pigments circulate with the blood and are
often contained in specialized cells.
• Greatly increases the amount of oxygen that
can be transported throughout the body
Oxygen Transport
Due to evolution many types of respiratory
pigments have evolved but the two main one
are:
• Hemocyanin- found in arthropods and uses
copper as it’s oxygen-binding agent which
makes the blood bluish.
• Hemoglobin- is the respiratory pigment of
almost all vertebrates and a wide variety of
invertebrates.
Hemoglobin
• Consists of four subunits with a cofactor called
a Heme group that contains an iron at the
center.
• Each Hemoglobin molecule can hold four
molecules of oxygen.
Partial Pressure
• Partial Pressure is the pressure which the gas
would have if it alone occupied the volume.
• Partial pressure influences the diffusion of
oxygen and carbon dioxide across respiratory
systems by moving the molecules from higher
concentrations to lower concentrations. This is
why carbon dioxide and oxygen move from to
and from cells to reach the same
concentration on both sides.
Dissociation Curve and the Bohr Shift
• Dissociation Curve- is a graph that shows the
percent saturation of hemoglobin at various
partial pressures of oxygen.
• Bohr shift- is the shift of oxygen dissociation
curve to the right with a drop in pH because
the hydrogen ions affect the conformation of
hemoglobin therefore lowering the percent
saturation of oxygen.
Dissociation Curve
• dissociation curve relates oxygen saturation
(SO2) and partial pressure of oxygen in the
blood (PO2)
• Hemoglobin's affinity for oxygen increases as
successive molecules of oxygen bind.
Carbon Dioxide Transport
• As a class simplify the steps of the carbon
dioxide transport that takes place in the
blood.
• Carbon dioxide is picked up at the tissues and
deposited in the lungs
Page 893
Respiratory Adaptations
• Diving Mammals- the Weddell seal of
Antarctica can store large amounts of oxygen
in its blood. Unlike humans the seals stock pile
70 percent of its oxygen in its blood and only 5
percent in its small lungs. Humans hold 36
percent of our oxygen in our lungs and 51
percent in our blood.
• Myoglobin- is an oxygen storing protein found
in the muscles of diving mammals
Respiratory System
• http://www.youtube.com/watch?v=BTuzGBPE
qbA&feature=related
• Brightstorm