Gas Transport

How is most oxygen transported in the blood?

bound to hemoglobin

Where does hemoglobin load oxygen?

In the lungs

Where does hemoglobin unload oxygen?

In the tissues

How many oxygen molecules can one hemoglobin bind?

4

What determines how much O₂ binds to hemoglobin?

PO₂

What is the O₂-Hb dissociation curve?

Relationship between PO₂ and Hb saturation

Why is the plateau phase important?

Provides a safety margin for oxygen loading

What does increased PCO₂ do to hemoglobin?

Promotes O₂ release

Why does CO₂ lower pH?

Forms Carbonic Acid

What effect does low pH (acidic conditions) have?

Shifts curve right → more O₂ released

Anemia

Reduced ability to carry O2

What does increased temperature do?

Promotes O₂ unloading

Law of Mass Action

concentration of one substance involved in a reversible reaction is increased O2 reaction is driven toward opposite side

What gas binds Hb more strongly than O₂?

Carbon monoxide (CO)

Why is carbon monoxide dangerous?

Prevents oxygen from binding to hemoglobin

Steep Phase

represents the blood PO2 range in the systemic capillaries where O2 is unloaded

Shifting curve to the right

represents a lesser affinity for O2 and greater release of O2

Diamox

lowers pH of blood flushes out bicarbonate

Where does CO₂ conversion to bicarbonate occur?

in red blood cells

What is the Hamburger phenomenon?

Chloride shift that maintains ion balance

Physical factors after hemoglobin’s affinity for oxygen

effect of pH, effect of Hemoglobin, effect of PCO2, and effect of the metabolic compound 2,3 BPG