Heam Flashcards
Carboxyheamglobin is generated how
CO binds to ferrous, Haemoglobin has a higher affinity fir CO so outcompetes o2.
Metheamaglobin is generated how
When fe2+ is oxidised fe3+ imperaing o2 binding
What colour does metHb give is present at high levels
Blood is blue/chocolate if present
Low levels of metHb causes o2 discosiation curve to shift where
Left- o2 not readily released causing anoxia
What enzyme is responsible for the catalysis of metHb back to Hb
Methemoglobin reductase
Metheamoglobinaemia is a what type of disorder
Heridiarty
Lack in methaglobin reductase
Or mutant form of Hb called Haemoglobin M which is resistant to enzyme
Also by exposure to some chemicals
Sickle Hb / HbS
Is caused by what
Mutation of codon 6 on b chain
Glutamic acid to valine
Polar soluble charged to non polar insoluble not charged
HbS soluble or insoluble
Insoluble
How does HbS form sickle
It polymerises from factoid and distort the rbc shape
Sickle blood cells are heamolysis
Faster only last for 20 days
Lower Hb conc
Form gall stones from inc rbc breakdown
What’s vaso occlusion
Blockage to micro vascular circulation
What does vaso occlusion cause
Infarction - tissue death
Pain
Dysfunctional
What shift does HbS cause
Right
More readily give 02 as HbS is lower affinity to 02
Cycle of HbS
Hypoxia causes polymerisation of HbS Causes sickle ing of rbc More prone to heamolysis Reduces rbc survival Causing anemia, gallstone
Or
Vaso occlusion
Affects many organs like Brain kidney lung
When do sky pens appear
4 to 6 months as fetal switch to adult Hb
