haemoglobin Flashcards
what kind of light does oxygenated haemoglobin absorb compared to deoxy?
Oxygenated haemoglobin absorbs more infrared light but less red light than deoxygenated haemoglobin.
Explain the electrophoresis results of Haemoglobin A and S
normal haemoglobin A (A) ran further towards the positive electrode (bottom of gel) than sickle haemoglobin (S). Since opposite charges attract, it can be concluded that HbA is more negatively charged than HbS.
what is the difference in charge due to in the electrophoresis results
This difference in charge is due to a point mutation occurring in one amino acid of the β-chain. In this mutation, the amino acid glutamate in the normal protein (hydrophilic, negatively charged) is replaced by valine (hydrophobic, uncharged)
how are Carboxyhaemoglobin and Methaemoglobin generated
Carboxyhaemoglobin (CoHb) is generated by the binding of carbon monoxide to ferrous iron (Fe2+) in haemoglobin.
Methaemoglobin (MetHb) is generated when the Fe2+ ion is oxidised to the Fe3+ (ferric) state which results in greatly impaired oxygen binding.
what do the spectrophotometry results between oxy haemoglobin and deoxyhaemoglobin look like
oxy has two main peaks at 540nm and 580nm
de oxy has one main peak at 560nm
what is a pulse oximeter
non invasive way of measuring oxygen saturation, measures difference in absorbance between oxyhaemoglobin and deoxyhaemoglobin
what colour does blood full of methaemoglobin turn
what do low levels of methaemoglobin result in
what does methaemoglobin reductase do
blue/ chocolate
oxygen dissociation curve to shift leftwards, resulting in tissue anoxia as oxygen is not readily released
reduce methaemoglobin back to haemoglobin
what are the causes methaeglobinaemia
hereditary disease
can be caused by deficiency in methaemoglobin reductase
or production of mutant form of haemoglobin called haemoglobin M - resistant to reduction
acquired following chemical exposure to anilines such as p chloro-aniline, nitrates, and local anaesthetics such as benzocaine
