Transcript Gas Exchange and Transport

Gas Exchange and
Transport
Unit D – Human Systems
Concentration Gradients


Gases diffuse from an area of high
pressure to an area of low pressure…they
move with the concentration gradient.
Oxygen is found in a greater concentration
outside of the body than inside our cells, so
oxygen flows towards our cells.


Carbon dioxide is present in a larger
concentration inside the cells of our body in
comparison to the air, so carbon dioxide
flows out of the body to our external
environment.
Gas Exchange Animation
Oxygen Transport



Oxygen is not very soluble in blood.
A protein called hemoglobin increases the
oxygen-carrying capacity of the blood.
Hemoglobin proteins contains iron atoms,
which are the part of the hemoglobin
molecules that bind with oxygen.
Oxyhemoglobin




Is formed when oxygen dissolves into the
plasma (liquid part of blood).
Hemoglobin binds with oxygen to form
oxyhemoglobin.
Formation of oxyhemoglobin increases the
amount of oxygen that is able to dissolve
into the bloodstream.
Oxygen Transport Animation
Carbon Dioxide Transport


Carbon dioxide is approximately 20 times
more soluble than oxygen.
Carbon dioxide combines with water found
in the plasma to form carbonic acid:
Carbon Dioxide Transport
Animation

By converting carbon dioxide to carbonic
acid, this keeps the concentration of carbon
dioxide low, so that carbon dioxide (waste
product) will continue to be picked up from
cells and released from the lung to
atmosphere.

However, the formation of too much acid
could change the pH of the blood and
possibly be fatal, so the carbonic acid must
be neutralized.
Student Tasks for Lesson


Complete textbook questions #1-5 on page
291.
Draw a flowchart showing air flow from the
nasal cavity to the lungs, including the
reactions of carbon dioxide and oxygen
transport.