EXAM 3 Flashcards
** How many ATP are utilized in the Gamma-glutamyl cycle to resynthesize glutathione?
- ) 2 ATP
- ) 4 ATP
- ) 1 ATP
- ) 3 ATP
4 (3 ATP)
** 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.
** Alanine aminotransferase converts alpha-ketoglutarate into glutamate and alanine into:
- ) Pyruvate
- ) Aspartate
- ) Oxaloacetate
- ) Glutamate
1.
** Elevations in BUN indicate increased load of ammonia. Checking the OA profile, you find high orotate levels, which could indicate there is a genetic SNP in the enzyme _____________.
- ) ornithine transcarbamoylase (OTC)
- ) argininesuccinate synthetase (ASS)
- ) argininosuccinate lyase (ASL)
- ) arginase
1
** AST, ALT, CPK, and _____ are all enzymes that can be indicators of liver damage, which in turn means impaired liver function.
- ) gamma-glutamyl transpeptidase
- ) gamma-glutamyl cyclotransferase
- ) pyroglutaminase
- ) GSH synthase
1.
** 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 A
A.
** True or False: Phosphofructokinase 1, Glucokinase, and Pyruvate Kinase are all upregulated in response to insulin.
T
** 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.
**Copper-containing ferroxidases called Hephaestin and __________ convert Fe2+ to Fe3+ so it can be safely transported by transferrin in the bloodstream
Ceruloplasmin
** Which transporter assists in uptake of iron from the intestines?
- ) Divalent metal transporter 1 (DMT1)
- ) Ferritin
- ) Ferrireductase duodenal cytochrome b
- ) Transferrin
1.
** 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
** 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
** 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
**True or False: Phosphofructokinase 1, Glucokinase, and Pyruvate Kinase are all upregulated in response to insulin.
T
** 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
High ATP will shut down phosphofructokinase and pyruvate kinase of glycolysis to slow production of more ATP
** The Alanine Cycle:
- ) Does not require ATP
- ) Occurs in a well-fed state
- ) Releases alanine from the liver
- ) None of these responses
4
Alanine cycle converts 2 alanine from peripheral tissue into glucose in the liver during a FASTING state
Requires ATP and produces 5-7ATP in peripheral tissues
of ATPs produced in peripheral tissues via Cori v. Alanine cycle
Cori = 2
Alanine = 5-7
** Advanced glycation end-products (AGEs) are created when glucose reacts spontaneously with ___(a)___ on proteins to create ____(b)___ products that spontaneously and irreversibly degrade to form AGEs.
- ) (a) amino acids, (b) Maillard reaction
- ) (a) amino acids, (b) Fenton reaction
- ) (a) organic acids, (b) Maillard reaction
- ) (a) organic acids, (b) Fenton reaction
1.
** The first step in the formation of heme (porphyrinogen pathway) involves the substrates glycine and succinyl CoA being converted to _(a)__ by the enzyme (b).
- ) (a) delta-aminolevulinic acid, (b) delta-aminolevulinic acid synthase
- ) (a) ALA, (b) ALA dehydratase
- ) (a) succinate, (b) succinate dehydrogenase
- ) (a) hydroxymethylbilane, (b) hydroxymethylbilane snythase
1
** Porphyrias can occur from prolonged fasting because low glucose intake leads to:
- ) upregulation of ALAS1
- ) downregulation of ALAS1
- ) upregulation of ALA dehydratase
- ) downregulation of ALA dehydratase
1
** ALA + ALA -> porphobilinogen via the enzyme (a) which requires (b).
- ) (a) delta-ALA dehydratase, (b) Zinc
- ) (a) ALA synthase, (b) Zinc
- ) (a) porphobilinogen deaminase, (b) NH3
- ) (a) hydroxymethylbilane synthase, (b) NH3
1
** GI conjugase enzymes hydrolyze folate to the monoglutamate form. What cofactor is needed for this reaction?
- ) Vitamin C
- ) Zinc
- ) Copper
- ) Magnesium
2
** 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
** 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
** 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
** 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
** T/F BPG increases in anemia, smoking, and at high altitudes forcing the reaction to the left to RELEASE oxygen more easily from the Hb by decreasing the affinity of Hb to O2
T
** 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
** 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
** 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
** 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
** 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 X X?
Free-fatty acids
** During heme degradation, which degradation product of bilirubin gives urine its yellow color?
Urobilin
** 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
** Glucagon rises in a fasting state and controls metabolism by:
- ) Blocking glycolytic enzymes
- ) Inhibiting glycogen synthase
- ) Increases PEP-carboxykinase
4) All of the above
4
** 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
** 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
4 early symptoms of diabetes (hint: poly…)
- Polyuria (increased urination)
- Polydypsia (increased thirst)
- Polyphagia (increased appetite/eating)
- Blurred vision
** 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
** 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
AGE v RAGE
AGE = advanced glycation end product (burnt/carmalized foods)
RAGE = receptor for advanced glycation end-product
T/F hemoglobinA1c is the process of glycation
T; glycation binds sugar to hemoglobin A
** 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
** 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
** 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 Sideroblastic anemia is an X-linked condition where the enzyme called ____________________ is mutated, leading to excess iron in the RBC mitochondria.
3 (also enzyme that control rate limiting step in heme synthesis)
** Elevations in Cortisol have been implicated in insulin resistance. Which of the following is NOT an action of high cortisol levels?
- ) Increased FA synthesis
- ) Increased gluconeogenesis
- ) Upregulation of GLUT4 receptors
- ) Increased glycogenolysis
3
When MCV is >100 associated with what type of anemia? When MCV is <80?
<80 = microcytic anemia (iron)
> 100 = macrocytic (megaloblastic) anemia (B9/12)
The storage form on iron is?
Ferritin
Ferrous v Ferric
Ferric = F3+ (needs to be reduced to be utilized)
Ferrous = F2+, reduced form found in hemoglobin
** 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
T/F Transferrin levels are increased when Fe is low
T
** 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
T/F TfR1 (transferrin receptor 1) is decreased during Fe deficiency?
F; it’s increased to help improve transport into the cell
What is the Fenton Reaction? Why is is a problem?
Fe2 + H202 —> Fe3 + OH (HYDROXYL/FREE RADICAL) + OH-
Hydroxyl radical is a dangerous free radical that causes lipid peroxidation and generates other fee radicals (that can damage tissues)
** 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
** 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
** 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
What enzyme is the rate limiting step of heme synthesis?
Delta-ALA synthase
** 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
** Folic Acid is composed of (what 3 things?)
- Pterin
- PABA
- Glutamic acid
** 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
** 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
** Glutathione is composed of what 3 things?
- Gamma-glutamyl (Glutamic acid)
- Cysteinyl
- Glycine
** 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
** 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
What MTHFR polymorphism leads to instability of the enzyme and less conversion of folic acid to 5MTHFR? What cancers are increased in elderly with this polymorphism?
C677T
Colon cancer
What mineral is at the center of B12’s structure?
Cobalt
define pernicious anemia
Is a macrocytic anemia caused by an autoimmune condition that causes no intrinsic factor
IF is needed to carry B12 into the intestines for absorption
MMA is a specific marker for X deficiency and FIGLU is a specific marker for Y deficiency?
X = B12
Y = Folic acid
** 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
**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
** Iodothyronine deiodinase 2 converts T4 to T3. What cofactor is needed for proper function?
Selenium
** 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
** Genetic mutations deactivating leptin or its receptor lead to? (2)
Hyperphagia
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
** 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
**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