Hemoglobin Flashcards
What is the function of hemoglobin?
Transports oxygen from lungs to the
tissues and transports Carbon Dioxide (CO2) from the
tissues to the lungs.
What is the concentration of hemoglobin?
Approximately 34g/dL with a
molecular weight of 64,000 daltons
Hgb comprises _____ of the cytoplasmic content of
RBCs.
95%
What is the shape of globular protein?
Spherical in shape
What are the reasons why Hgb are in the RBCs?
o Protection from denaturation
o So that it does not get lost to the kidneys.
The first protein whose structure was described using
X-ray crystallography.
Hemoglobin
Heme consists of a ring of carbon, hydrogen, and nitrogen atoms called?
Protoporphyrin IX
What does the 4 globin chains comprise?
Two identical pairs of unlike polypeptide chains.
Heme-Globin ratio:
1:1
1 hemoglobin is equal to 4 oxygen. Their iron will
bind with oxygen from ferrous to ferric. Once it
become ________, hemoglobin may not further take
_______.
Ferric; Oxygen
Heme consists three elements:
Carbon, Hydrogen,
& Nitrogen.
embedded within the heme group
Ferrous iron:
What is the abnormality in the sickle-hemoglobin?
A substitution of proteins in the polypeptide
chains.
Quaternary structure is also known as?
Tetramer
Amino acids’ structure.
Primary structure
Pertains to the arrangement: helix or non-helix
Secondary structure
Characterized by the “Pretzel” formation of the
helixes.
Tertiary structures
4,4,4: 4 heme, 4 globin, and 4 oxygen
Quaternary structure
Where does heme biosynthesis occur?
Mitochondria and cytoplasm
Which is located in the chromosome 16?
Alpha
Zeta
chromosome 11
epsilon, gamma, delta, and beta-globin gene
cluster
Where does the production of globin chains take place?
Erythroid precursors
Heme inhibits the transcription of
the ALA synthase gene, which leads to a decrease in
heme production (negative feedback mechanism)
Heme regulation
mainly controlled at the
transcription level by a complex interaction of DNA
sequences. It is also regulated during translation when
mRNA coding for the globin chains associates with
ribosomes to produce the polypeptide
Globin regulation
When there is an insufficient quantity of hemoglobin or
if the hemoglobin molecule is defective in transporting
oxygen, tissue _______ occurs.
Hypoxia
Hypoxia is detected by the ________________ of the
kidney, which responds by increasing the production of
erythropoietin (EPO).
Petribular cells
EPO increases the number of erythrocytes produced
and released into the ____________
Periphery
