560D CLINICAL BIOCHEMISTRY Flashcards
Which of the following factors can increase likelihood of getting iron deficiency anemia?
a. All of these responses can increase the risk of getting iron deficiency anemia
b. Heavy menstruation
c. Celiac disease
d. Deficiency of copper
a. All of these responses can increase the risk of getting iron deficiency anemia
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.
a. Hepcidin
b. Aconitase
c. Vitamin B12
d. Folic acid
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
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
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
a. Carnitine
Inhibition of CoQ10 synthesis from statin drugs, will typically reveal elevations in urinary_____________________.
a. Hydroxymethylglutarate
b. Hydroxymethylbutyrate
c. Hydroxymethylpropionate
d. Hydroxymethylsuccinate
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
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)
a. Di(2-ethylhexyl) phthalate (DEHP)
What does the Fenton Reaction do?
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?
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?
DMT-1 requires H+, which comes from stomach acid
Deficiency of which nutrients increase the risk of iron deficiency anemia? (2)
Vitamin C and copper
What is the only active and functional porphyrin in the heme synthesis pathway?
Protoporphyrin IX
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?
- ) Vitamin B12
- ) Folic Acid
- ) Intrinsic factor
- ) Vitamin C
4.) Vitamin C
Antacids can reduce the absorption of iron and copper, leading to iron deficiency anemia because:
- ) Because the antacids bind the metals
- ) Acidic pH increases Fe3+
- ) DMT1 requires co-transport of H+ ions to internalize divalent cations
- ) Stomach acid properly degrades metals
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?
- ) Celiac disease
- ) All of these responses
- ) Heavy menstruation
- ) Deficiency of copper
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.
- ) (a) NADPH, (b) NADP+
- ) (a) NADH, (b) NADPH
- ) (a) NADP+, (b) NADPH
- ) (a) NAD+, (b) NADH
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
- ) Decreased pH (acidity)
- ) High altitude
- ) Increased 2,3-Bisphosphoglycerate
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.
- ) Vitamin B12
- ) Aconitase
- ) Hepcidin
- ) Folic Acid
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.
- ) Protoporphyrin IX oxidase
- ) NADH methemoglobin reductase
- ) Delta-aminolevulinic acid synthase
- ) Diaphorase I
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
A: Ferritin (this is an intracellular storage form of iron)
Which transporter assists in uptake of iron from the intestines?
- ) Divalent metal transporter 1 (DMT1)
- ) Ferritin
- ) Ferrireductase duodenal cytochrome b
- ) Transferrin
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:
- ) Increased pC02 and increased pH
- ) Increased pCO2 and decreased pH
- ) Decreased pC02 and decreased pH
- ) Decreased pC02 and increased pH
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:
- ) Succinyl CoA and Methylmalonyl CoA
- ) Methylmalonyl CoA and homocysteine
- ) Acetyl CoA and homocysteine
- ) Succinyl CoA and homocysteine
2.) Methylmalonyl CoA and homocysteine
Elevations of FIGLU in the urine can indicate:
- ) Functional deficiency of vitamin B12
- ) Functional deficiency of histidine
- ) Functional deficiency of glutamate
- ) Functional deficiency of folic acid
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 _______________.
- ) 5,10 Methylene-THF
- ) 5-Methyl-THF
- ) THF
- ) 10-Formyl-THF
2.) 5-Methyl-THF
GI conjugase enzymes hydrolyze folate to the monoglutamate form. What cofactor is needed for this reaction?
- ) Zinc
- ) Vitamin C
- ) Copper
- ) Magnesium
1.) Zinc
Alanine aminotransferase converts alpha-ketoglutarate into glutamate and alanine into:
- ) Pyruvate
- ) Aspartate
- ) Oxaloacetate
- ) Glutamate
1.) Pyruvate
Folic Acid is composed of:
A: Pterin, PABA, Glutamic acid
What cofactor assists aminotransferases like ALT and AST in their ability to transfer amino groups?
- ) Pyridoxal-5-Phosphate
- ) Vitamin B5
- ) Pyridoxamine Phosphate
- ) Vitamin C
1.) Pyridoxal-5-Phosphate
Pyridoxal-5-Phosphate (B6) is required by all aminotransferases, actually holds onto the amino group that gets transferred during the enzymatic process, and gets recycled for continual use in these reactions.
How many ATP are utilized in the Gamma-glutamyl cycle to resynthesize glutathione?
- ) 2 ATP
- ) 4 ATP
- ) 1 ATP
- ) 3 ATP
4.) 3 ATP
Gamma-glutamyl transpeptidase (GGT) is responsible for breaking down ……(a)…… into ____(b)____
- ) (a) GSH, (b) gamma-glutamylAA + cysteinylglutamate
- ) (a) GSH, (b) gamma-glutamylAA + cysteinyl-oxoproline
- ) (a) GSH, (b) gamma-glutamylAA + cysteinylglycine
- ) (a) GSH, (b) gamma-glutamylAA + cysteinylglutamine
3.) (a) GSH, (b) gamma-glutamylAA + cysteinylglycine
Thyroperoxidase (TPO) is responsible for catalyzing the following reaction(s):
- ) Iodination, joining of Iodine to thyroglobulin
- ) Coupling of DIT with DIT to form T4
- ) Oxidization of Iodide to Iodine
- ) Coupling of MIT with DIT to form T3
- ) All of these responses
5.) All of these responses
Which of the following interfere with Iodide uptake and utilization by the thyroid:
- ) Goitrogenic Foods like soy and uncooked cruciferous vegetables
- ) Low ATP
- ) Low TSH
- ) Competing halogens like bromide and chloride
- ) All of these responses
5.) All of these responses
What minerals are actively symported into the thyroid follicular cell from the bloodstream for the creation of thyroid hormones?
- ) Iodine and Selenium
- ) Iodide and Sodium
- ) Iodide and Potassium
- ) Iodide and Magnesium
2.) Iodide and Sodium
How can decreased levels of thyroid hormone impact vitamin A?
- ) Impairs function of vitamin A
- ) Impairs conversion of beta-carotene to vitamin A
- ) Impairs absorption of vitamin A
- ) Impairs release of vitamin A
2.) Impairs conversion of beta-carotene to vitamin A
Iodothyronine deiodinase 2 converts T4 to T3. What cofactor is needed for proper function?
A: Selenium
Genetic mutations deactivating leptin or its receptor lead to:
A: Hyperphagia and massive obesity
Clients may be diagnosed as overweight if their BMI is:
- ) 30-34.9
- ) 18.5-24.9
- ) 35-39.9
- ) 25-29.9
4.) 25-29.9
High levels of ATP in the cell indicate increased energy reserves. Hence, high levels of ATP will:
- ) Appear during a fasting state
- ) Enhance activity of glycogen phosphorylase
- ) Enhance activity of isocitrate dehydrogenase
- ) Block activity of pyruvate kinase
4.) Block activity of pyruvate kinase
High ATP will shut down phosphofructokinase and pyruvate kinase of glycolysis to slow production of more ATP.
True or False: Phosphofructokinase 1, Glucokinase, and Pyruvate Kinase are all upregulated in response to insulin.
A: True
Intra-abdomial (visceral/organ) fat is more dangerous than subcutaneous fat because it:
- ) Increases inflammatory cytokines
- ) May increase insulin resistance and ER stress
- ) All of these responses
- ) Increases free FA
3.) All of these responses
The Cori cycle:
- ) All of these responses
- ) Converts 2 lactate into glucose
- ) Is upregulated in a fasting state
- ) Produces 2 ATP in peripheral tissues
1.) All of these responses
Obesity and chronic overnutrition interrupt metabolic pathways in the following way(s):
- ) High NADH reduces creation of Acetyl CoA and TCA cycle
- ) All of these responses
- ) High ATP reduces glycolysis and TCA cycle
- ) High pyruvate and acetyl CoA increase FA
- ) Excess glucose converts to glycogen
2.) All of these responses
The Alanine Cycle:
- ) Does not require ATP
- ) Occurs in a well-fed state
- ) Releases alanine from the liver
- ) None of these responses
4.) None of these responses
Alanine cycle converts 2 alanine from peripheral tissue into glucose in the liver during a fasting state, requires ATP and produces 5-7 ATP in peripheral tissues.
Hyperglycemia can lead to glycation (glycosylation) reactions. One such glycation reaction with hemoglobin A, leads to Hemoglobin A1c, which can be measured in the bloodstream and is a marker for how much a person’s blood sugar has fluctuated over the past 3 months. What level of HbA1c is indicative of Diabetes?
- ) 5.7-6.4
- ) > or = 7.0
- ) < 5.7
- ) > or = 6.5
4.) > or = 6.5
Peroxisome Proliferator Activated Receptor (PPAR) are important in FA and glucose metabolism. Nutrients and activities that can assist in activation of these receptors include:
- ) Exercise
- ) Zinc and Magnesium
- ) All of these responses
- ) Vitamin E
- ) PUFA and 9-cis-retinoic acid
3.) All of these responses
Insulin Resistance leads to increased cardiovascular disease risks through:
- ) Increased PAI-1
- ) Increased inflammation through peroxidation
- ) All of these responses
- ) Increased TG, VLDL, and LDL
3.) All of these responses
Glucagon rises in a fasting state and controls metabolism by:
A: All of these responses
- ) Blocking glycolytic enzymes
- ) Inhibiting glycogen synthase
- ) Increases PEP-carboxykinase
A: All of these responses
Glucagon blocks glycolysis, increases gluconeogenesis (PEP-carboxykinase) and decreases glycogenesis (glycogen synthase).
Metabolic Syndrome (Syndrome X) is a combination of metabolic changes including hypertension, insulin resistance, and dyslipidemia. The dyslipidemia is characterized by:
- ) Decline in TG
- ) Decline in HDL
- ) Decline in VLDL
- ) Decline in LDL
2.) Decline in HDL
During heme degradation, which degradation product of bilirubin gives urine its yellow color?
A: Urobilin
One of the maladaptive responses in insulin resistance includes dyslipidemia. Increased activity of vascular lipoprotein lipase leads to increased chylomicron and VLDL release of non-esterified or:
A: Free-fatty acids
Non esterified fatty acids = Free FA
The correlation of hyperinsulinemia and increases in hypertension come from the hyperinsulinemia causing:
- ) Increased sodium retention and uric acid retention
- ) Improved thermogenesis
- ) Increased potassium retention
- ) Increased blood flow to peripheral tissues
1.) Increased sodium retention and uric acid retention
Difficulty losing weight with insulin resistance comes from the body’s inability to increase body heat from increased decoupling of the ETC and oxidative phosphorylation (and hence remove excess energy from carbohydrates and lipids as heat). This process is called:
- ) Metabolic Syndrome
- ) Obesity
- ) Thermogenesis
- ) Diabetes Mellitus
3.) Thermogenesis
Obstruction of the bile duct from gallstones (called extrahepatic cholestasis) can cause symptoms of pale clay colored stools and dark urine upon standing. This occurs because:
- ) The liver regurgitates stercobilin into the blood and the decline of urobilinogen entering the GI tract
- ) The liver regurgitates conjugated bilirubin into the blood and the decline of conjugated bilirubin entering the GI tract
- ) The liver regurgitates unconjugated bilirubin into the blood and the decline of unconjugated bilirubin entering the GI tract
- ) The liver regurgitates biliverdin into the blood and the decline of heme entering the GI tract
2.) The liver regurgitates conjugated bilirubin into the blood and the decline of conjugated bilirubin entering the GI tract
Delta-aminolevulinic acid (ALA synthase) creates delta-aminolevulinic acid from what substrates?
- ) Succinyl CoA and heme
- ) Succinyl CoA and iron
- ) Succinyl CoA and glycine
- ) Succinyl CoA and vitamin B12
3.) Succinyl CoA and glycine
The reabsorption of urobiliogens from the GI to the liver so they can be resecreted into the bile is called the______________.
- ) Enterohepatic Urobiliogen Cycle
- ) Hepatosplenic Urobilinogen Cycle
- ) Entersplenic Urobilinogen Cycle
- ) Enterohepatic Stercobilin Cycle
1.) Enterohepatic Urobiliogen Cycle
Hyperbilirubinemia can lead to Jaundice, yellowing of the skin, nail beds and whites of the eyes. Acute hemolytic crises found in G6PD deficiency and Sickle Cell Anemia can cause hyperbilirubinemia and jaundice from an:
- ) Increase in stercobilin and urobilinogen
- ) Increase in unconjugated bilirubin only
- ) Increase in conjugated bilirubin only
- ) Increase in unconjugated and conjugated bilirubin
4.) Increase in unconjugated and conjugated bilirubin
Which enzyme in the heme biosynthesis pathways contains zinc and is located in the cytosol?
- ) Delta-ALA Dehydratase
- ) Hydroxymethylbilane Synthase
- ) Uroporphyrinogen Decarboxylase
- ) ALA Synthase
1.) Delta-ALA Dehydratase
This enzyme converts 2 ALA into porphobilinogen and is very sensitive to heavy metals like lead because they replace the zinc.
How many ATP are needed to create active ALA synthase (to fold it, activate it, and transport it into the term-51mitochondria)?
- ) 3 ATP
- ) 4 ATP
- ) 2 ATP
- ) 1 ATP
3.) 2 ATP
The first step in heme degradation utilizes heme oxygenase to create biliverden. What reductant is required for this pathway to function?
- ) GTP
- ) NADH
- ) NADPH
- ) ATP
3.) NADPH
How can porphyrias arise from a low caloric (low glucose) diet?
- ) Because ALAS1 will be downregulated to push the heme biosynthesis pathway
- ) Because Delta-ALA dehydratase will be upregulated in the heme biosynthesis pathway
- ) Because ALA synthase 1 will be upregulated to push heme biosynthesis.
- ) Because Delta-ALA dehydratase will be downregulated in the heme biosynthesis pathway
3.) Because ALA synthase 1 will be upregulated to push heme biosynthesis.
Glucose inhibits ALAS1, so it is automatically upregulated in the absence of glucose. This is why glucose is given IV to people with acute porphyrias and why it is important for people with porphyrias to avoid crash dieting and low carb diets.
What is the abbreviation for Glutamine?
- ) Gln
- ) Glt
- ) Glu
- ) Gly
1.) Gln
What are the four conditionally essential amino acids?
- ) Arg, Gln, Gly, Ser
- ) Arg, Glu, Gly, Tau
- ) Arg, Glu, Gly, Ser
- ) Arg, Gln, Gly, Tau
4.) Arg, Gln, Gly, Tau
List the large neutral AA:
- ) Trp, Tyr, Phe, Leu, Ile, Val
- ) Trp, Thr, Phe, Leu, Ile, Met
- ) Trp, Thr, Phe, Leu, Ile, Val
- ) Trp, Tyr, Phe, Leu, Ile, Met
4.) Trp, Tyr, Phe, Leu, Ile, Met
If there is a defect in the SN1-SN2 transporter allowing Gln into the presynaptic nerve terminal, what will happen to Glu levels within the presynaptic nerve terminal?
- ) Glu levels will decline unless the EEAC1 receptor can compensate
- ) Glu levels will increase unless the EEAC1 receptor can compensate
- ) Glu levels will increase unless the GLAST receptor can uptake Glu into the perineuronal astrocyte
- ) Glu levels will decline unless the GLAST receptor can uptake Glu into the perineuronal astrocyte
1.) Glu levels will decline unless the EEAC1 receptor can compensate
GS (Glutamine Synthetase) requires the use of what minerals to assist in the conversion of Glu -> Gln?
- ) Mg++, Se++
- ) Se++, Mn++
- ) Mg++, Zn++
- ) Mg++, Mn++
4.) Mg++, Mn++
NH3 is ___(a)___ and acts to help buffer __(b)__ environments.
- ) (a) mildly basic, (b) acidic
- ) (a) mildly basic, (b) basic
- ) (a) mildly acidic, (b) basic
- ) (a) mildly adicic, (b) acidic
1.) (a) mildly basic, (b) acidic
In the urea cycle, Citrulline combines with Aspartate to form ______________ via the enzyme ASS (argininosuccinate synthase/synthetase).
- ) Argininoglutarate
- ) Argininomalate
- ) Argininoaspartate
- ) Argininosuccinate
4.) Argininosuccinate
In the urea cycle, Arginase requires what cofactor to convert Arg -> Orn + urea?
- ) Mn++
- ) Mg++
- ) Cu++
- ) Zn++
1.) Mn++
A defect in the urea cycle enzyme argininosuccinate lyase, will lead to the accumulation of what substrate?
- ) Fumarate
- ) Argininosuccinate
- ) Arginine
- ) Citrulline
2.) Argininosuccinate
In the urea cycle, CPS (mitochondrial carbamoyl phosphate synthase 1) converts ammonia + H2O + 2 ATP + CO2 -> ______________.
- ) Carbamoyl phosphate + AMP + diphosphate
- ) Carbamoyl phosphate + SO4, 2 ADP
- ) Carbamoyl phosphate + PO4 + AMP
- ) Carbamoyl phosphate + PO4 + 2 ADP
4.) Carbamoyl phosphate + PO4 + 2 ADP
The pathway Arg -> Orn + a-KG -> -> Pro for the creation of collagen via the enzymes arginase, ornithine aminotransferase and pyrroline-5-carbosylate reductase require what nutrients for proper activity?
- ) Mn++, B5, retinoic acid, B3, Mg++
- ) Mn++, P5P, B5, B3, Mg++
- ) Zn++, B5, retinoic acid, B3, Mg++
- ) Mn++, P5P, retinoic acid, B3, Mg++
4.) Mn++, P5P, retinoic acid, B3, Mg++
Arg -> ADMA via PRMT (methionine dependent protein arginine N-methyltransferase) requires what nutrient?
- ) SAH
- ) Homocysteine
- ) Met
- ) SAMe
4.) SAMe
BCAA are converted to alpha-ketoacids via BCAA transaminase. This enzyme requires the cofactor:
- ) B3
- ) B6
- ) B5
- ) B2
BCAA are converted to alpha-ketoacids via BCAA transaminase. This enzyme requires the cofactor:
- ) B3
- ) B6
- ) B5
- ) B2
Branched Chain Ketoacid Dehydrogenase Complex (BCKDC) attaches Coenzyme A (CoA) to alpha-ketoacids. The nutrients utilized in this reaction as either substrate or cofactors are:
1.) B2, B3, B5, Lipoic Acid
2.) B1, B3, B5, B6, Lipoic Acid
3,) B1, B2, B3, B6, Lipoic Acid
4.) B1, B2, B3, B5, Lipoic Acid
4.) B1, B2, B3, B5, Lipoic Acid
Lysine does NOT undergo the initial transamination requiring B6 but downstream conversion of alpha-aminoadipic acid (a-AAA) to alpha-ketoadipate does require B6. What nutrient is required for the initial conversion of Lys -> Saccharopine?
- ) B2
- ) B12
- ) B5
- ) B3
4.) B3
Phenylalanine Hydroxylase (PAH) requires what nutrients for conversion of Phe -> Tyr?
1) Copper, B2, BH4
2. ) Copper, B3, BH4
3. ) Iron, B2, BH4
4. ) Iron, B3, BH4
4.) Iron, B3, BH4
What two nutrients are required by both tyrosine hydroxylase (TH) and phenylalanine hydroxylase (PAH)?
- ) Iron, Vitamin C
- ) Copper, Vitamin C
- ) Vitamin C, tetrahydrobiopterin
- ) Iron, tetrahydrobiopterin
4.) Iron, tetrahydrobiopterin
Conversion of norepinephrine -> epinephrine via the enzyme Phenylethanolamine-N-Methyltransferase (PNMT) utilizes what nutrient in this reaction?
- ) Copper
- ) Iron
- ) SAMe
- ) Vitamin C
3.) SAMe