Hemoglobin Model

Hemoglobin model: note the 02 being carried by molecule.
Pipe cleaners=subunits
Green marsh mellow=iron molecule

Yellow marsh mellow=oxygen molecule
Orange cards= heme groups
(wolfe, 2000)
Oxygenated/deoxygenated
oxygenated
• 02 bound
• Bright red
• Subunit is in relaxed form
• Higher affinity for 02
• Affinity for oxygen is cooperative, which means that the affinity for 02 increases with each bound molecule.
( Ahern & Rajagopal, 2013)
Deoxygenated
• 02 not bound
• Dark red color
• In tense form which has lower
affinity for oxygen.
• When 02 binds to deoxygenated hemoglobin, hemoglobin transitions from T state to R state. This occurs when 02 binds to iron, it causes a change in the subunit. ( Ahern & Rajagopal, 2013)
Bohr Effect
Hemoglobin has a high affinity for 02 at a high PH, low Co2. Hemoglobin has a lower affinity at a low PH, high Co2. At a high Co2, low PH hemoglobin is more stable in the T state which decreases its affinity for 02. Oxygen needs to be delivered to the tissues. Tissues have a low PH. Hemoglobin needs to release 02 at low PH. Low PH = low 02 saturation. ( Wolfe,2000 )
Myoglobin: wants to store 02 for when tissues need it. Has a higher affinity than hemoglobin. ( Ahern & Rajagopal, 2013)
Hemoglobin: wants to unload 02 in the tissues. Has a lower affinity than myoglobin. ( Ahern & Rajagopal, 2013 ) (Genetic science learning center, 2013)
Difference between normal and sickle forms of hemoglobin.
Normal and sickle RBC’s at the cellular level. (Genetic science learning center, 2013)
Diseased RBC’s vs. Normal RBC’s
Diseased
• Have a sickle shape, and are thick and sticky. Clumps together in small blood vessels.
• Blocks normal hemoglobin to deliver 02 to tissues.
• Short life p of 10-20 days
• Body can not keep up with rbc production leading to anemia and pain. (Wolfe, 2000)
Normal
• Round
• Doughnut shape
• Life p of 120 days
(Wolfe, 2000) (Ahern and Rajagopal, 2013)