Hemoglobin metabolism Flashcards
most studied protein in the body due to its
ability of being easily isolated from the RBC
hemoglobin
what compromises 95% of the rbc?
cytoplasmic content of rbc
what is the ring carbon, hydrogen and nitrogen called in the heme structure?
protoporphyrin IX
what is the oxidized hemoglobin called?
methemoglobin
when ferrous oxidized become ____ it cannot bind with?
ferric; oxygen
each hemoglobin has how many globin chains?
4
what is amino acid sequence of polypeptide chain called?
primary structure
what structure have chain arrangements in helices and nonhelices
secondary structure
what structure has the arrangement of helices into pretzel like configuration
tertiary structure
what structure have a complete hemoglobin structure>
quaternary structure
it has two a globin chain and b globin chain
Hb A
posttranslational modification
formed by the nonenzymatic binding of sugars
to globin chain amino groups
glycation
Occurs in mitochondria and cytoplasm of bone marrow
erythroid precursor
hemoglobin biosynthesis
epsilon, gamma, delta, and beta is on the short arm of?
chromosome 11
where does production of globin chain occurs?
erythroid precursors
transcription of globin genes to mRNA happens in
nucleus
transformation of mRNA to the globin polypeptide chains occurs in
ribosomes in cytoplasm
globin binds to heme molecule and forms>
heterodimer
it comprises of 2 a chain and 2 b chain and present from 6 months of age through adulthood
Hb A
contains of a 2 a chain and 2 d chains and comprises less than 3.5% of total hemoglobin in adults
Hb A2
contains two a and two g chains
Hb F
Used for fractionation, presumptive identification,
and quantification of normal hemoglobin and
hemoglobin variants
Electrophoresis and HPLC
what is the is the predominant hemoglobin at the 2nd and 3rd trimesters of fetal life and at birth
Hb F
what is the predominant at 6 months of age and through
adulthood with small amounts of Hb A2 and Hb F2
Hb A
what is the key rate-limiting step in heme synthesis is the initial reaction of _____
glycine and succinyl CoA to form ALA
it leads to balance production of heme and globin
globin regulation
when is globin synthesis regulates ?
translation
insufficient quantity of hemoglobin leads to?
hypoxia
hypoxia is detected by
peritubular cells of kidney
EPO increases the number of?
erythrocytes
what is the amount of oxygen needed to saturate 50% hemoglobin
p value
shift to the left in oxygen means?
o2 bound to RBC, high % of o2 saturation
shift to right in oxygen
low o2 saturation o2 is deliver to tissue and no o2 is delivered to the lungs
Causes relaxation of vascular wall smooth
muscle and vasodilation
nitric oxide
dysfunctional hemoglobin that are unable to transport oxygen
dyshemoglobin
Formed by the reversible oxidation of heme iron to the
ferric state
methhemoglobin
