pack Flashcards
What does hemoglobin consist of?
4 heme groups inside 4 globin chains
What are the types of globin chains?
Alpha (a)
Beta (B)
Gamma (γ)
Delta (δ)
What are the types of hemoglobin?
Hemoglobin A
Hemoglobin A2
Hemoglobin F
What are the characteristcs of Hemoglobin A? How common/rare is it?
Structure: a2b2
Rarity: most common type in adults (95%)
What are the characteristcs of Hemoglobin A2? How common/rare is it?
– Less common type (2-3%) –
α2 δ2
What are the characteristcs of Hemoglobin F? How common/rare is it?
Fetal type
α2 γ2
What is unique about the affinity of Hb f?Why does it have this unique feature?
It has higher affinty to oxygen than Hb A because the fetus competes with the mother for oxygen bc of growth.
What does 2,3-Bisphosphoglycerate do?
Promotes O 2 release from hemoglobin by Decreasing oxygen affinity of hemoglobin
and Increasing delivery oxygen to tissues
When does the synthesis of 2,3-biphosphoglycerate increase?Why does it increase?
In high altitudes bc of hypoxia
characteristcs of Taut hb form (T)
Low O2 affinity
tends to release oxygen
favored in tissues
(bc when you are tense you like to be left alone)
characteristcs of Relaxed hb form (R)
High O2 affinity
Tends to hold on to oxygen
favored form in lungs
(bc when you are relaxed you like seeing people and holding on to them)
What are the characteristcs of tissues that make it favor the hb taut form?
Low ph
High h+,CO2
O2 released for use
What are the characteristcs of lungs that make it favor the hb relaxed form?
Low pH
Low H+, O2
Binds O2 to carry to tissues
What is cooporative binding?
The first O2 to bind to hemoglobin increases the affinity to make it easier for the rest of the O2 to bind
What is hemoglobing Oxygen saturation?
from the name, It is the percentage of Oxyhemoglobin to the total hemoglobin in the body.
Example: You have 10 hemoglobin in total, 5 of those hemoglobins are oxyhemoglobins, so you have 50% oxygen saturation.
What are allosteric effectors?
Effectors that don’t directly bind to the oxygen binding sites but still affect the binding of oxygen to hemoglobin.
Include:
2,3 BPG
Temp
PH
CO2
What causes the curve to shift to the right?
lower affinity, bc you will have more oxygen dissolved in the blood with the same amount of oxygen in the hemoglobin
What factors cause the curve to shift to the right?
Higher acidity
Higher CO2
Higher temp
Higher BPG
What causes the curve to shift to the right?
Higher affinity bc there is more Oxyhemoglobin for the same amount of dissolved oxygen
What are the affects of carbon monoxide on oxygen and heme?
Carbon monoxide binds to oxygen binding sites (heme)
This causes less space available for oxygen
If a carbon monoxide molecule binds to heme, it increases the affinity of the other heme groups, causing oxygen to not be released when needed.
What does Carbon monoxide do the oxygen dissassociation curve?
It shifts the curve to the left due to the higher affinity, and decreases the carrying capacity.
What are some of the symptoms of carbon monoxide poisoning?
Headaces
malaise, nausea, dizziness
IMPORTANT: Cherry red skin bc carboxyhemoglobin is red.
What is Methemoglobinemia?
Normally hemoglobin contains iron in the ferrous form (fe+2)
but certain drugs oxidize it to fe+3
and the fe+3 (Like CO) will increase the affinity of the other heme (fe+2) molecules
What type of curve shift is caused by Methemoglobinemia?
left due to higher affinity
What are the symptoms of Methemoglobinemia?
Cyanosis (bluish skin color),
fatigue, dizziness, headache, shortness of breath
