560D CLINICAL BIOCHEMISTRY EXAM
QUESTIONS AND ANSWERS
Which of the following factors can increase the likelihood of getting iron
deficiency anaemia?
a. All of these responses can increase the risk of getting iron deficiency
anaemia
b. Heavy menstruation
c. Celiac disease
d. Deficiency of copper - ANSWER a. All of these responses can
increase the risk of getting iron deficiency anaemia
Anaemia of chronic disease can be caused by prolonged inflammation
(IL-6, cytokines, infection), which increases the level of
__________________ to sequester iron in tissues so germs can't use
the iron to reproduce.
a. Hepcidin
b. Aconitase
c. Vitamin B12
d. Folic acid - ANSWER a. Hepcidin
What are the four conditionally essential amino acids?
a. Arg, Gln, Gly, Tau
b. Arg, Gln, Gly, Ser
c. Arg, Glu, Gly, Tau
d. Arg, Glu, Gly, Ser - ANSWER a. Arg, Gln, Gly, Tau
Mutations in the SN1-SN2 transporter can lead to elevations in what 3
AA?
a. Gln, Asn, His
b. Glu, Asn, His
c. Glu, Asp, His
d. Gln, Asp, His - ANSWER a. Gln, Asn, His
The central energy pathways begin with digestion and assimilation of
fats, carbohydrates, and proteins. Long chain FA require the use of the
,_________________ shuttle to help them enter the mitochondrial for
beta-oxidation.
a. Carnitine
b. Malate
c. Aspartate
d. Carnosine - ANSWER a. Carnitine
Inhibition of CoQ10 synthesis from statin drugs, will typically reveal
elevations in urinary_____________________.
a. Hydroxymethylglutarate
b. Hydroxymethylbutyrate
c. Hydroxymethylpropionate
d. Hydroxymethylsuccinate - ANSWER a. Hydroxymethylglutarate
When considering toxic exposures, through what barriers and routes of
entry can lipophilic (fat loving) toxins be absorbed?
a. All of these responses
b. Through the GI tract
c. Through the skin
d. Through the lymphatics
e. In utero - ANSWER a. All of these responses
One of the phthalate esters used in plastic wrap to cover foods can lead
to decreased kidney function, increased cysts, increased peroxisome
proliferation and even liver cancer in rats. This is a concern to humans
because ________________ is used in plastic tubing for hemodialysis.
a. Di(2-ethylhexyl) phthalate (DEHP)
b. Dimethyl phthalate (DMP)
c. Diethyl phthalate (DEP)
d. Polyethylene terephthalate (PETE) - ANSWER a. Di(2-ethylhexyl)
phthalate (DEHP)
What does the Fenton Reaction do? - ANSWER It forms the toxic
hydroxyl radical, a form of reactive oxygen species, which causes lipid
peroxidation and formation of other free radicals
, What does DMT-1 transport, and what would be the impact of an excess
of any of these metals? - ANSWER DMT-1 transports iron, zinc, copper,
and manganese. Excess can inhibit absorption of the other metals
How would antacids and H2 blockers interfere with iron absorption? -
ANSWER DMT-1 requires H+, which comes from stomach acid
Deficiency of which nutrients increase the risk of iron deficiency anemia?
- ANSWER Vitamin C and copper
What is the only active and functional porphyrin in the heme synthesis
pathway? - ANSWER Protoporphyrin IX
Where is heme synthesis most pronounced? - ANSWER Bone marrow
and liver
What does Protoporphyrin IX convert to when heme is added? -
ANSWER Iron
What natural constituent non-enzymatically oxidizes porphyrinogens into
porphyrins and what part of the porphyrinogen structure is oxidized? -
ANSWER Porphyrinogens are unstable and light oxidizes them into
porphyrins by oxidizing the four methylene bridges
What enzyme controls the rate limiting step of heme synthesis? -
ANSWER Delta-aminolevulinic acid synthase (ALA synthase)
Where is ALA synthase active and what are the substrate and products
in the reaction? - ANSWER In the mitochondrial matrix; substrates are
succinyl CoA and glycine, product is delta-aminolevulinic acid
What is the required cofactor for ALA synthase? - ANSWER P5P/B6
How many ATP- dependent processes are necessary to activate Delta-
Aminolevulinic acid (ALA) synthase? - ANSWER Two
What is the difference between a porphyrinogen and a porphyrin? -
ANSWER A porphyrin is the oxidized form that is water insoluble