SBB COMPREHENSIVE TEST PAPER 2026
COMPLETE ANSWERS ACCURATE
⫸ ATP source for RBCs Answer: 90% from Glycolysis (Embden-
Meyerhoff pathway)
10% from pentose phosphate pathway
⫸ Methemoglobin Reductase Pathway Answer: necessary to maintain
heme iron in ferrous (Fe2+) state
Deficiency causes accumulation of methemoglobin, nonfunctional from
of Hgb
⫸ Leubering Rapaport Shunt Answer: permits accumulation of 2,3-
DPG
⫸ "Tense form" of Hgb Answer: DEOXYGENATED
widening of beta-chain
lower affinity for O2
expels 2,3-DPG
⫸ "Relaxed form" of Hgb Answer: OXYGENATED
beta-chain pulled together
higher affinity for O2
,expels 2,3-DPG
⫸ "Shift Right" Answer: higher P50 value
decreased pH (increased H+ ion), acidosis
increased 2,3-DPG
higher temperature
high pCO2
Seen in compensated anemia
⫸ "Shift Left" Answer: lower P50 value
increased pH (decresed H+ ion), alkalosis
decreasede 2,3-DPG
lower temeratures
low pCO2
Seen in storage of RBC
⫸ Type 2 precursor Answer: Gal-GlcNAc
B1-4
⫸ Type 1 precursor Answer: Gal-GlcNAc
B1-3
,Secreted (Se, Le)
⫸ Type 2 H antigen transeferase & Sugar Answer: FUT-1
Alpha-2-L-fucosyltransferase
Fuctose alpha1-2
⫸ A antigen transferase & sugar Answer: D-galactosaminetrasferase
N-acetylgalactosamine alpha1-3
⫸ B antigen transferase & sugar Answer: D-galacotsyltransferase
galactose alpha1-3
⫸ Ax subgroup Answer: weakly positive anti-A
weakly positive anti-A,B
⫸ Am subgroup Answer: Negative anti-A
Secretes A & H
, ⫸ Ael subgroup Answer: Negative anti-A
Secretes H only
⫸ Highest expression of H
Lowest expression of H Answer: O>A2>B>A2B>A1>A1B> H deficient
⫸ Lewis transferase & Sugar Answer: FUT-3
Fuctose alpha1-4
⫸ Type 1 H antigen transferase & sugar Answer: FUT-2
Fuctose alpha1-2
⫸ anti-Le bh vs anti-Le bl Answer: Anti-Le bh= reacts best with Leb &
H are on rbc
reacts best with group O and A2
does not react with A1 & B
Anti-Le bl= reacts independently of amount of H on rbc
best antisera to use when typing RBC
⫸ autoanti-H, -HI is most common in... Answer: A1 patients, have the
least amount of H
COMPLETE ANSWERS ACCURATE
⫸ ATP source for RBCs Answer: 90% from Glycolysis (Embden-
Meyerhoff pathway)
10% from pentose phosphate pathway
⫸ Methemoglobin Reductase Pathway Answer: necessary to maintain
heme iron in ferrous (Fe2+) state
Deficiency causes accumulation of methemoglobin, nonfunctional from
of Hgb
⫸ Leubering Rapaport Shunt Answer: permits accumulation of 2,3-
DPG
⫸ "Tense form" of Hgb Answer: DEOXYGENATED
widening of beta-chain
lower affinity for O2
expels 2,3-DPG
⫸ "Relaxed form" of Hgb Answer: OXYGENATED
beta-chain pulled together
higher affinity for O2
,expels 2,3-DPG
⫸ "Shift Right" Answer: higher P50 value
decreased pH (increased H+ ion), acidosis
increased 2,3-DPG
higher temperature
high pCO2
Seen in compensated anemia
⫸ "Shift Left" Answer: lower P50 value
increased pH (decresed H+ ion), alkalosis
decreasede 2,3-DPG
lower temeratures
low pCO2
Seen in storage of RBC
⫸ Type 2 precursor Answer: Gal-GlcNAc
B1-4
⫸ Type 1 precursor Answer: Gal-GlcNAc
B1-3
,Secreted (Se, Le)
⫸ Type 2 H antigen transeferase & Sugar Answer: FUT-1
Alpha-2-L-fucosyltransferase
Fuctose alpha1-2
⫸ A antigen transferase & sugar Answer: D-galactosaminetrasferase
N-acetylgalactosamine alpha1-3
⫸ B antigen transferase & sugar Answer: D-galacotsyltransferase
galactose alpha1-3
⫸ Ax subgroup Answer: weakly positive anti-A
weakly positive anti-A,B
⫸ Am subgroup Answer: Negative anti-A
Secretes A & H
, ⫸ Ael subgroup Answer: Negative anti-A
Secretes H only
⫸ Highest expression of H
Lowest expression of H Answer: O>A2>B>A2B>A1>A1B> H deficient
⫸ Lewis transferase & Sugar Answer: FUT-3
Fuctose alpha1-4
⫸ Type 1 H antigen transferase & sugar Answer: FUT-2
Fuctose alpha1-2
⫸ anti-Le bh vs anti-Le bl Answer: Anti-Le bh= reacts best with Leb &
H are on rbc
reacts best with group O and A2
does not react with A1 & B
Anti-Le bl= reacts independently of amount of H on rbc
best antisera to use when typing RBC
⫸ autoanti-H, -HI is most common in... Answer: A1 patients, have the
least amount of H
