Haemoglobin Flashcards
1
Q
what does haemoglobin carry?
A
- oxygen
- carbon dioxide
- nitric oxide
- excess glucose
2
Q
healthy adult has ___ - ___ g of haemoglobin for every 100 ml of blood
A
12 - 20g
3
Q
2/3 of haemoglobin is synthesised during …
A
erythroblast stage
4
Q
1/3 of haemoglobin is synthesised during…
A
reticulocyte stage
5
Q
haemoglobin structure
A
- globin - ball shape
- conjugated protein
- quartenary structure
- each subunit has 2 components - haem + globulin
6
Q
haem
A
- consists of a central iron atom held in a heterocyclic ring called porphyrin
- porpyhrin consists of 4 pyrrole molecule cyclically linked by methane bridges
- haem synthesis mainly occurs in mitochindria
7
Q
globulin
A
- each globulin consists of polypeptide chains that help keep iron in ferrous state
- synthesis occurs mainly in polyribosomes
8
Q
fetal haemoglobin
A
- higher affinity for O2 - ensuring its transferred from maternal blood
- PO2 is very low due to high metabolic rate associated with fetal growth rates
- at birth fetal Hb replaced with adult type Hb
9
Q
fetal haemoglobin variant
A
HbF (a2y2)
10
Q
does haemoglobin have positive or negative cooperativity?
A
positive
11
Q
what does positive cooperativity mean with examples?
A
- e.g - when deoxyhaemoglobin binds a single oxygen, other haeme groups more likely to bind other oxygen molecules
- e.g - haemoglobin fully saturated, dissociating one oxygen makes other oxygen more likely to dissociate
12
Q
what shape is the oxygen-haemoglobin dissociation curve?
A
sigmoidal
13
Q
what are the x-axis & y-axis of oxygen-haemoglobin dissociation curve?
A
- x - partial pressure of oxygen
- y - % of haemoglobin that’s fully saturated with oxygen
14
Q
RBC reference range
A
- male : 4.3-5.7 * 10^12/L
- female: 3.9-5.0 * 10^12/L
15
Q
reticulocytes reference range
A
- male : 35-125 * 10^9/L
- female : 25-115 * 10^9/L
