Hemoglobin

What is the molecular structure of A hemoglobin?

2 alpha, 2 beta chains

Prevalence of A hemoglobin in adults vs newborns

Adults: >95% vs Newborns: 20%

What is the molecular structure of A₂ hemoglobin?

2 alpha, 2 delta chains

Prevalence of A₂ hemoglobin in adults vs newborns

Adults: 1.5-3.7% vs Newborns: <1%

What is the molecular structure of F hemoglobin?

2 alpha, 2 gamma chains

Prevalence of hemoglobin F in adults vs newborns

Adults: <2% vs Newborns: 50-85%

What is the molecular structure for S hemoglobin?

Valine substituted for glutamic acid on 6th position of beta chain

What is the molecular structure for C hemoglobin?

Lysine substituted for glutamic acid on the 6th position of the beta chain

What does hemoglobin electrophoresis look like on cellulose acetate @pH 8.6? (crawl, slow, fast, accelerated)

Origin

I Cathode(-) A₂/C S F A Anode(+)

What does hemoglobin electrophoresis look like on citrate agar @pH 6.2? (fast, accelerated, slow, crawl)

Origin

Cathode(-) F A/A₂ I S C

Name the 3 types of hemoglobin derivatives

Methemoglobin

Sulfhemoglobin

Carboxyhemoglobin

What is the cause of Methemoglobin?

Iron is oxidized into ferric state usually acquired from exposure to oxidants. Its rarely inherited.

What is the effect of methemoglobin?

Hemoglobin can’t bind to O₂ possibly leading to cyanosis or death

What is the cause of sulfhemoglobin?

Sulfur is bound to heme, which is acquired from exposure to drugs and chemicals

What is the effect of sulfhemoglobin?

O₂ affinity 1/100th normal (binding to oxygen is very weak at a single binding site) and cyanosis

What is the effect of carboxyhemoglobin?

Carbon monoxide is bound to heme

What is the effect of carboxyhemoglobin?

Decrease of O₂ to tissues and can be fatal