Structure and function of normal red blood cells Flashcards
red blood cells have a many ————– to keep the ion concentrations right
sodium-potassium pumps
sodium potassium pumps help
keep water out
what is the structure of hemoglobin?
2 alpha chains and 2 beta chains
hemoglobin is a ——————- protein
tetrameric globular
what is the heme group?
fe2+ and flat porphyrin ring
how many heme groups are there?
one heme per subgroup
one oxygen molecule binds to
one Fe2+
what are the functions of haemoglobin?
deliver oxygen to tissues
act as a buffer for H+
CO2 transportation
where is the hypoxia sensor located?
in the juxtaglomerular apparatus in the kidneys
erythropoietin is produced in the?
kidneys
erythropoietin stimulates ———— to undergo hyperplasia?
erythron
the erythron is located in the?
bone marrow
what are the raw materials required to make red blood cells?
iron, folate and B12
what type of response is red cell production?
negative feedback
where does red cell destruction normally take place?
spleen (and liver)
what is the average life-span of red blood cells
120 days
which cells take out aged red cells?
macrophages
the globe chains are recycled to?
amino acids
what is the heme group broken down to?
iron and bilirubin
bilirubin is taken to?
liver and conjugated
conjugated bilirubin is present in?
bile (colors faeces and urine)
lots of free radicals are generated from?
the oxygen present around the red cell
how can freee radicals cause challenges for red cells?
they oxidize Fe2+ to Fe3+
damage proteins
what is the glycolysis pathway called?
embed-meyerhof pathway
what is sacrificed to prevent oxidation of Fe2+ to Fe3+
NADH
what is Fe3+ called?
metHB
what prevents oxygen from becoming superoxide?
superoxidase dismutase
what does superoxide cause?
interacts with proteins, DNA etc and damages their structure
what converts hydrogen peroxide to water?
peroxidase catalase
superoxide is converted to?
hydrogen peroxide
what protects us from hydrogen peroxide by reacting with it to form water?
glutathione
when glutathione reacts with hydrogen peroxide you get?
water and an oxidized glutathione product
how is oxidized glutathione replenished?
NADPH
what generates NADPH?
the hexose monophosphate shunt
what is the rate-limiting enzyme in this process?
glucose-6-phosphate dehydrogenase
majority of CO2 is transported as?
bicarbonate
in tissues Co2 and water make?
H2CO3
what enzymecatalyses Co2 and Water?
Carbonic anhydrase
H2CO3 then forms?
H+ and HCO3- and Cl-
where does Cl- come from?
it enters to presence potential
how is H= buffered?
by deoxygenated Hb
how is HCO3- exported?
facilitated diffusion between Cl-
what is the Hb allosteric effect?
as one oxygen bind to a subunit the Hb changes shape and this alters how easy it is for the next O2 to bind to a different subunit changing shape again, cooperative binding
what is different about foetal hemoglobin?
as maternal blood flows through the placenta at the same partial pressure, there is increased foetal hemoglobin saturation than normal haemoglobin saturation
small molecules can interact with Hb and?
affect the shape of the curve and how much oxygen is delivered to the tissues
in chronic anaemia what pathway is activated?
Rapapoport-Lubering shunt
this is when 1,3 bisphosphoglycaerate is converted to?
2,3,BPG
2,3, BPG causes the curve to shift?
to the right resulting in more O2 delivered to tissues
