560D Clinical Biochem Final UPDATED ACTUAL Exam Questions and CORRECT Answers

560D Clinical Biochem Final UPDATED
ACTUAL Exam Questions and CORRECT
Answers
A client with diagnosed iron deficiency anemia comes to you because he eats meat based protein
and green leafy vegetables but his iron levels have not increased. What other nutrient is needed
to properly absorb iron?


1.) Vitamin B12
2.) Folic Acid
3.) Intrinsic factor

4.) Vitamin C - CORRECT ANSWER - 4.) Vitamin C


Antacids can reduce the absorption of iron and copper, leading to iron deficiency anemia
because:


1.) Because the antacids bind the metals
2.) Acidic pH increases Fe3+
3.) DMT1 requires co-transport of H+ ions to internalize divalent cations

4.) Stomach acid properly degrades metals - CORRECT ANSWER - 3.) DMT1 requires co-
transport of H+ ions to internalize divalent cations


Which of the following factors can increase likelihood of getting iron deficiency anemia?


1.) Celiac disease
2.) All of these responses
3.) Heavy menstruation

4.) Deficiency of copper - CORRECT ANSWER - 2.) All of these responses

,Glucose-6-phosphate dehydrogenase is the enzyme that reduces .......(a)....... to ____(b)____ as
part of the hexose monophosphate shunt pathway (ie. pentose phosphate pathway). G6PD
deficiency can lead to RBC hemolysis from oxidant stress because ___(b)___ is no longer
available to help recycle glutathione.


1.) (a) NADPH, (b) NADP+
2.) (a) NADH, (b) NADPH
3.) (a) NADP+, (b) NADPH

4.) (a) NAD+, (b) NADH - CORRECT ANSWER - 3.) (a) NADP+, (b) NADPH


Sickle Cell Anemia is caused by a point mutation leading to a structural instability of the RBC.
What conditions can create increased stress, leading to increased levels of deoxyhemoglobin and
sickle cell crisis?


A: All of these responses
1.) Decreased pH (acidity)
2.) High altitude

3.) Increased 2,3-Bisphosphoglycerate - CORRECT ANSWER - A: All of these responses


Anemia of chronic disease can be caused from prolonged inflammation (IL-6, cytokines,
infection), which increases level of __________________ to sequester iron in tissues so germs
can't use the iron to reproduce.


1.) Vitamin B12
2.) Aconitase
3.) Hepcidin

4.) Folic Acid - CORRECT ANSWER - 3.) Hepcidin (Is synthesized by the liver and controls
iron homeostasis).


Sideroblastic anemia is an X-linked condition where the enzyme called ____________________
is mutated, leading to excess iron in the RBC mitochondria.

,1.) Protoporphyrin IX oxidase
2.) NADH methemoglobin reductase
3.) Delta-aminolevulinic acid synthase

4.) Diaphorase I - CORRECT ANSWER - 3.) Delta-aminolevulinic acid synthase (this is also
the enzyme that controls the rate limiting step in heme synthesis)


Copper-containing ferroxidases called Hephaestin and __________ convert Fe2+ to Fe3+ so it
can be safely transported by transferrin in the bloodstream - CORRECT ANSWER - A:
Ferritin (this is an intracellular storage form of iron)


Which transporter assists in uptake of iron from the intestines?


1.) Divalent metal transporter 1 (DMT1)
2.) Ferritin
3.) Ferrireductase duodenal cytochrome b

4.) Transferrin - CORRECT ANSWER - 1.) Divalent metal transporter 1 (DMT1)


The Bohr effect explains that a decrease in the amount of oxygen associated with hemoglobin
(Hb) due to a reduced affinity of oxygen for Hb is the result of:


1.) Increased pC02 and increased pH
2.) Increased pCO2 and decreased pH
3.) Decreased pC02 and decreased pH

4.) Decreased pC02 and increased pH - CORRECT ANSWER - 2.) Increased pCO2 and
decreased pH


pCO2 (partial pressure of carbon dioxide)

, It is important to simultaneously check vitamin B12 and folate levels because administration of
folic acid can mask vitamin B12 deficiency, leading to neurological demyelination that is often
irreparable. The 2 constituents that accumulate in B12 deficiency, one of which competitively
inhibits FA biosynthesis leading to increased myelin sheath turnover/degradation are:


1.) Succinyl CoA and Methylmalonyl CoA
2.) Methylmalonyl CoA and homocysteine
3.) Acetyl CoA and homocysteine

4.) Succinyl CoA and homocysteine - CORRECT ANSWER - 2.) Methylmalonyl CoA and
homocysteine


Elevations of FIGLU in the urine can indicate:


1.) Functional deficiency of vitamin B12
2.) Functional deficiency of histidine
3.) Functional deficiency of glutamate

4.) Functional deficiency of folic acid - CORRECT ANSWER - 4.) Functional deficiency of
folic acid


The folate trap occurs when there is deficient amounts of vitamin B12 and folate gets "trapped"
in the form _______________.


1.) 5,10 Methylene-THF
2.) 5-Methyl-THF
3.) THF

4.) 10-Formyl-THF - CORRECT ANSWER - 2.) 5-Methyl-THF


GI conjugase enzymes hydrolyze folate to the monoglutamate form. What cofactor is needed for
this reaction?