Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
53 Cards in this Set
- Front
- Back
|
Tryptophan serves as a precursor for what?
A. serotonin only B. serotonin & melatonin C. serotonin, melatonin, & niacin D. serotonin, melatonin, & tyrosine E. serotonin, niacin, & phenylalanine |
C. serotonin, melatonin, & niacin.
|
|
|
The following is a true statement regarding noncompetitive inhibitors:
A. They compete with substrate for the binding site. B. they bind irreversibly to the enzyme at a site other than the binding site C. they raise the Km D. they increase the Vmax E. their effect on enzyme is independent of substrate concentration |
E. their effect on enzyme is independent of substrate concentration
Noncompetitive enzyme inhibitors don't bind the active site (substrate binding site).Thus, they don't compete with substrate for binding to the enzyme.Their effect on enzyme is independent of substrate concentration (vs. competitive enzyme inhibitors that do bind to the enzyme's active site, competing with substrate for binding to the enzyme-and,substrate concentration significantly affects their degree of binding). |
|
|
A patient in a research study is described as having a glutamic acid residue in the beta-globin chain of hemoglobin that is replaced by a valine. What may be the eventual outcome for this patient?
A. autosplenectomy B. mental retardation C. beta-hemolytic strep D. beta-thalassemia E. spherocytosis |
A. autosplenectomy. ). This case describes the underlying anomalies associated with sickle cell disease. Each episode of RBC sickling (a "crisis") results in splenomegaly with concomitant splenic inflammation. Recurrent episodes of this splenic injury causes splenic damage and fibrosis. Thus, the spleen is destroyed; this process is known as autosplenectomy.
|
|
|
Normal eukaryotic mRNA processing includes the following:
A. addition of a 3’-polyadenylate tail B. addition of a poly-A tail + a 5’ 7-methyl-guanosine cap C. adding of a 3’ poly A tail, a 5’ cap, & splicing of exons together with removal of introns D. addition of 4’ poly A tail, a 5’ cap & splicing of introns together with removal of exons E. addition of a 3’ poly A tail, & development of the anticodon loop & the 3’ acceptor stem |
C. adding of a 3’ poly A tail, a 5’ cap, & splicing of exons together with removal of introns
|
|
|
What alcohol derived from glucose is responsible for development of cataracts in diabetics?
A. ethanol B. sorbitol C. galacitol D. glycerol E. methanol |
B. sorbitol. Only sorbitol is related to cataract development in diabetics. It is produced when excess glucose enters the lens; sorbitol, once formed, cannot diffuse out of the cells in which it was formed.
|
|
|
Which of the following is a true statement regarding nonsteroidal anti-inflammatory agents (NSAIDS)?
A. they encourage the formation of thromboxanes B. they increase prostaglandin levels C. they decrease arachidonic acid levels D. they inhibit cyclooxygenase E. they inhibit lipoxygenase |
D. they inhibit cyclooxygenase.
|
|
|
Which of the following does not inhibit Na-K ATPase?
A. corticosteroids B. digoxin C. ouabain D. cardiotonic steroids E. digitalis |
A. corticosteroids
|
|
|
Which of the following work to block oxidative phosphorylation via blockade of the electron transport chain?
A. rotenone only B. rotenone & cyanide C. rotenone, cyanide, & amytal D. rotenone, cyanide, amytal, & carbon monoxide E. rotenone, cyanide, amytal, carbon monoxide, & oligomycin |
D. rotenone, cyanide, amytal, & carbon monoxide.
|
|
|
What sugar is manufactured in the seminal vesicle to provide a major energy source for spermatozoa but not for other tissues in contact with it?
A. fructose B. glucose C. galactose D. sucrose E. lactose |
A. fructose. In the seminal vesicle, glucose is converted to sorbitol via aldose reductase. That sorbitol is then converted to fructose via sorbitol dehydrogenase. That fructose is manufactured in the seminal vesicle to act as a major energy source for spermatozoa, but not for other tissues that come in contact with the seminal fluid.
|
|
|
Which of the following are direct inhibitors of the pyruvate dehydrogenase complex?
A. NADH & acetyl CoA B. NADPH & acetyl CoA C. NAD alone D. NAD & acetyl CoA E. Acetyl CoA only |
A. NADH & acetyl CoA.
Pyruvate dehydrogenase complex (PDC) functions, via 3 steps, to convert pyruvate (the end product of glycolysis) to acetyl CoA (acetyl coenzyme A), a precursor for the citric acid cycle (Krebs cycle). PDC is inhibited by its products: acetyl CoA and NADH. Conversely, stimulants to PDC activity are pyruvate (its substrate), insulin, NAD, and calcium. |
|
|
What tissues are gluconeogenic?
A. liver & kidney B. small intestine epithelium, liver, & kidney C. brain, liver, & kidney D. muscle, brain, & liver E. liver only |
B. small intestine epithelium, liver, & kidney
|
|
|
A young child is determined to suffer from pre-prandial hypoglycemia and is found to have hepatomegaly. What possible enzyme deficiency may exist?
A. glycogen synthase B. glucose-6-phosphatase C. muscle glycogen phosphorylase D. glucokinase E. hepatic glycogen phosphorylase |
E. hepatic glycogen phosphorylase.
Pre-prandial hypoglycemia and hepatomegaly are common features of disorders of glycogenolysis (breakdown of glycogen to glucose) that are specific to the liver. The liver plays a vital role, via glycogenolysis, to provide glucose for blood sugar homeostasis, especially between meals. Deficiency in hepatic glycogen phosphorylase, an enzyme critical to glycogen metabolism in liver,will yield hepatomegaly and pre-prandial hypoglycemia, yielding a disease known as Her's disease. |
|
|
What is the underlying derangement that yields the hemolysis associated with exacerbated G6PD deficiency?
A. decreased glutathione reductase activity B. decreased glutathione peroxidase activity C. inadequate levels of reduced glutathione D. inadequate levels of hydrogen peroxide E. excess glucose-6-phosphate dehydrogenase activity |
C. inadequate levels of reduced glutathione.
Glucose-6-phosphate dehydrogenase is the enzyme that allows for entry into the pentose phosphate shunt pathway (the oxidative branch) from the pentose phosphate pathway. It uses glucose-6-phosphate to produce NADPH from NADP. The newly synthesized NADPH is used to convert oxidized glutathione (GS-SG) to reduced glutathione (GSH), the active form of glutathione. The latter reaction is catalyzed by glutathione reductase. The active form of glutathione (reduced glutathione) then engages in a reaction, catalyzed by glutathione peroxidase, that converts tissue damaging organic peroxides (R-O-OH) to neutral, non-damaging forms (R-OH+H20). If one has G6PD deficiency, tissue-damaging organic peroxides accumulate. And, since this is the only mechanism that RBCs have for eradicating such molecules, the RBCs are hemolyzed. So, the deficiency in glucose-6-phosphate dehydrogenase causes glutathione deficiency. |
|
|
Fatty acids are easily transported from the cytoplasm into the mitochondrion via the carnitine cycle. However, during fatty acid synthesis, this movement is prevented to block wasteful beta-oxidation of newly formed fatty acids. What molecule, present as part of fatty acid synthesis, acts as an inhibitor to the carnitine cycle?
A. acetyl CoA B. acetoacetyl CoA C. palmitoyl CoA D. malonyl CoA E. succinyl CoA |
D. malonyl CoA.
Malonyl CoA is formed from acetyl CoA via acetyl CoA carboxylase, and is the rate-limiting step in fatty acid synthesis. Hence, when malonyl CoA levels are elevated, it is an indication that fatty acid synthesis is underway. So, there is a mechanism to prevent fatty acid metabolism during fatty acid synthesis (e.g., synthesis and breakdown pathways are blocked from occurring simultaneously). This mechanism is as follows: malonyl CoA inhibits the carnitine cycle. The carnitine cycle is the process whereby fatty acids destined for breakdown are transported from the cytoplasm into the mitochondrion. Once inside the mitochondrion, beta-oxidation of fatty acids to yield energy is undertaken. The carnitine cycle is directed by carnitine palmitoyl transferase I and II, enzymes located to the mitochondrial inner membrane. So, carnitine palmitoyl transferase I and II are inhibited by malonyl CoA to ensure newly synthesized fatty acids aren't metabolized |
|
|
What is the mitochondrial & extra-mitochondrial product, respectively, of HMG-CoA?
A. ketone bodies; cholesterol B. ketone bodies; ketone bodies C. cholesterol; ketone bodies D. cholesterol; cholesterol E. acetyl CoA; cholesterol |
A. ketone bodies; cholesterol.
HMG CoA reductase is an enzyme found only in the cytoplasm (and, therefore, extra-mitochondrial). It functions to convert HMG CoA (beta-hydroxy-beta-methylglutaryl coenzyme A) to mevalonic acid, the rate-limiting step in cholesterol synthesis. Mevalonic acid is then converted to produce cholesterol. Hence, HMG CoA that is extra-mitochondrial is a precursor to cholesterol. Conversely, HMG CoA is converted to ketone bodies in the mitochondrion. |
|
|
For what molecules does cholesterol act as the precursor molecule?
A. pregnenolone & progesterone B. progesterone & cortisol C. pregnenolone & aldosterone D. pregnenolone, progesterone, cortisol & aldosterone E. pregnenolone, progesterone, cortisol, aldosterone, & testosterone |
E. pregnenolone, progesterone, cortisol, aldosterone, & testosterone
|
|
|
What enzyme is necessary for eventual prostaglandin production?
A. phospholipase A1 B. phospholipase A2 C. phospholipase C D. phospholipase D E. lipoxygenase |
B. phospholipase A2
|
|
|
What is the precursor molecule to the production of melanin, dopamine, norepinephrine, epinephrine, & thyroxine?
A. histidine B. arginine C. glutamate D. tyrosine E. tryptophan |
D. tyrosine
|
|
|
What is the normal metabolism associated with hemoglobin degradation?
A. biliverdin then bilirubin then bilirubin diglucuronide then heme B. bilirubin then bilirubin diglucuronide then biliverdin then heme C. heme then bilirubin then bilirubin diglucuronide then biliverdin D. heme then biliverdin then bilirubin then bilirubin diglucuronide E. heme then biliverdin then bilirubin diglucuronide then bilirubin |
D. heme then biliverdin then bilirubin then bilirubin diglucuronide.
Hemoglobin is degraded to heme and globin. Heme oxygenase catalyzes the conversion of heme into biliverdin, a green-colored molecule. Then, biliverdin reductase catalyzes the conversion of biliverdin to bilirubin, a red-colored molecule. Bilirubin is transported to the liver where it is conjugated to (added to) glucuronic acids, to produce water-soluble bilirubin diglucuronide. |
|
|
Which of the following is a true statement regarding metabolism in the diabetic?
A. the low insulin/glucagon ratio inhibits gluconeogenesis & glycogenolysis B. the high glucagon/insulin ratio stimulates hepatic gluconeogenesis & glycogenolysis, contributing to hyperglycemia C. the rate of ketone body production is about the same as that seen in starvation D. the Type I diabetics without insulin experience decreased adipose tissue lipolysis & decreased glucose uptake into skeletal muscles, liver, adipocytes E. all tissues suffer glucose deficiency because of the insulin derangements experienced with all types of diabetics |
B. the high glucagon/insulin ratio stimulates hepatic gluconeogenesis & glycogenolysis, contributing to hyperglycemia
|
|
|
What dietary deficiency results in inadequate conversion of homocysteine to methionine, thereby preventing the conversion of intracellular methyl-THF (tetrahydrofolic acid) to free THF?
A. folic acid B. cobalamin C. niacin D. cystathionine E. thiamine |
B. cobalamin. Cobalamin, also known as cyanocobalamin or vitamin B12, serves as a cofactor for methionine synthesis from homocysteine. Thus, vitamin B12 serves to reduce homocysteine levels. However, the reaction itself occurs concurrently with the production of methyl tetrahydrofolate (methyl THF) to free THF. Free THF is then used as the precursor to methylene THF.
|
|
|
Which of the following is correctly matched with an accurate description of its activity?
A. helicase; induces (-) DNA supercoils for tight DNA packing within cells B. gyrase, induces (+) DNA supercoils, thereby unwinding the DNA for replication C. DNA-dependent RNA polymerase; synthesizes DNA from RNA D. primase; synthesizes DNA from RNA topoisomerase I E. topoisomerase I;relaxes supercoiled DNA by nicking one strand & then resealing it after it unwinds one turn |
E. topoisomerase I;relaxes supercoiled DNA by nicking one strand & then resealing it after it unwinds one turn
|
|
|
The TATA Box, the CAAT box, & the GC box are all important components of what?
A. eukaryotic promoter B. eukaryotic coding region C. housekeeping genes D. the Shine-Dalgarno sequence E. prokaryotic promoter |
A. eukaryotic promoter.
The eukaryotic promoter to RNA synthesis is comprised of, in order from 5' to 3', the CAAT box, the GC box, and the TATA box which, itself, is about 25 bases upstream from the start site.The TATA box is critical for proper chain initiation in RNA synthesis.The GC box, not always present, is more typically a component of promoters for housekeeping genes, genes that must be continuously active rather than regulated. |
|
|
What type of base change mutation results in premature termination of the resulting polypeptide?
A. silent B. nonsense C. missense D. transition E. transversion |
B. nonsense.
|
|
|
Which of the following is correctly matched with the effect it has on protein synthesis?
A. ricin; prevents translocation by ribosylating EF-2 B. streptomycin; blocks translocation C. erythromycin; causes misreading of prokaryotic mRNA at low concentrations D. diphtheria toxin; inactivates the 60S subunit E. tetracycline; blocks the A site preventing binding of aminoacyl-tRNA binding |
E. tetracycline; blocks the A site preventing binding of aminoacyl-tRNA binding
|
|
|
Amplified genes, such as those frequently seen in certain cancers, may be arranged in tandem arrays within the chromosome or may be cleaved out of the chromosome to become these extrachromosomal entities:
A. homeoboxes B. euchromatin C. zinc fingers D. double minute chromosomes E. heterochromatin |
D. double minute chromosomes. ). Amplified genes, such as those frequently encountered in cancer cells, may be arranged within the chromosome or may be cleaved out of the chromosome to form "double minute chromosomes". Because they have no centromere, they are incapable of replication during cell division.
|
|
|
PCR is a method used to amplify the DNA in small tissue samples from a crime suspect. What method is used to compare that DNA (representing that of the suspects) to the DNA of a forensic specimen?
A. DNA fingerprinting B. Northern blotting C. Southern blotting D. Western blotting E. Restriction |
A. DNA fingerprinting.
DNA fingerprinting allows for ID of genetic structure, and is used to analyze forensic DNA evidence. Restriction fragment length polymorphism (RFLP) is DNA that differs in length from other individuals' DNA after treatment with restriction enzymes. In DNA fingerprinting, DNA is procured from a forensic sample. Then, a region of that amplified (e.g., multiple copies are made) with PCR (polymerase chain reaction).Then, RFLPs from that forensic sample are compared to known RFLPs. |
|
|
What are the 2 messengers produced by the phosphoinositide cascade?
A. inositol triphosphate & diacylglycerol B. phosphatidyl inositol bisphosphate and GTP C. phospholipase C and arachidonic acid D. protein kinase C and phosphatidic acid E. inositol triphosphate and arachidonic acid |
A. inositol triphosphate & diacylglycerol
|
|
|
What is the cause for increased IP3 & DAG, and what is the result of this increase?
A. Gi protein activation; increased cAMP B. Gq protein activation; increased cytosolic calcium concentration C. Gi protein inhibition; decreased cAMP D. Gs protein activation; decreased cytosolic calcium concentration E. Go protein activation; decreased cytosolic calcium concentration |
B. Gq protein activation; increased cytosolic calcium concentration
|
|
|
Which of the following is a true statement regarding HDLs?
A. they transfer triglycerides to VLDL & LDL B. they provide apoCII to VLDLs & chylomicrons C. they form cholesterol from cholesterol esters D. they deposit cholesterol on blood vessel walls E. their numbers are decreased by exercise |
B. they provide apoCII to VLDLs & chylomicrons
|
|
|
In the retinal visual cycle, 11-cis retinal combines with opsin to form rhodopsin. When rhodopsin is exposed to light, it breaks down to release this:
A. free opsin & all trans retinol B. all trans retinol & 11-cis retinal C. opsin & 11-cis retinal D. 11-cis retinal & all trans retinal E. free opsin & all trans retinal |
E. free opsin & all trans retinal
All trans retinol is oxidized to all trans retinal in the retina. That all trans retinal is then converted to 11-cis retinal. Opsin combines with the 11-cis retinal to form the visual pigment known as rhodopsin. When rhodopsin is exposed to light, it is degraded to free opsin and all trans retinal. That all trans retinal is then converted to 11-cis retinal to start the retinal visual cycle all over again. |
|
|
What serum protein functions to transport iron in the blood?
A. hemosiderin B. apoferritin C. ferritin D. transferrin E. ceruloplasmin |
D. transferrin
|
|
|
What is apoferritin?
|
apoferritin is ferritin that has no iron bound to it.
|
|
|
What is ceruloplasmin?
|
ceruloplasmin is ferroxidase II, and functions to oxidize iron in the bloodstream to the form that will allow binding to transferrin.
|
|
|
What clotting pathway is initiated by tissue injury that causes the release of tissue factor, a glycoprotein on the surface of cells not normally in contact with blood?
A. intrinsic clotting cascade B. extrinsic clotting cascade C. common clotting cascade D. platelet aggregation pathway E. plasminogen pathway |
PT = Extrinsic. B. extrinsic clotting cascade
The extrinsic clotting cascade is initiated by tissue injury with the resulting release of tissue factor. Tissue factor activates factor VII which then activates X of the common clotting cascade. |
|
|
In the steps entering the urea cycle, CO2 & ammonium combine to form what molecule?
A. ornithine B. citrulline C. carbamoyl phosphate D. aspartate E. arginine |
C. carbamoyl phosphate. The first step in the urea cycle is the formation of carbamoyl phosphate from carbon dioxide and ammonium.
|
|
|
A 50 year old male presents with complaints of headache and bilateral heteronymous hemianopsia. In addition, he complains that he has begun to get blisters in areas where his old shoes are beginning to rub. What is the hormone that is responsible?
A. thyroid hormone B. ACTH C. aldosterone D. growth hormone E. insulin |
D. growth hormone. = acromegaly.
|
|
|
A female neonate born at 30-weeks’ gestation has hypoxemia, hyperpnea, an L/S ratio of 1.25. Chest X-ray demonstrates bilateral reticular lung infiltrates and atelectasis. What cells are responsible for this child’s maladies?
A. RBCs B. alveolar macrophages C. astrocytes D. type II pneumocytes E. type I pneumocytes |
D. type II pneumocytes.
This patient has acute respiratory distress syndrome (ARDS) of the infant. Any infant born before 32-weeks' gestation is at risk for developing ARDS because of underdeveloped type II pneumocytes, the cells responsible for surfactant production. Without adequate surfactant production, the lungs collapse, causing hypoxemia and hyperpnea. A clear indication of a deficit in surfactant amounts is an L/S (lecithin: sphingomyelin) ratio of less than 2.0. |
|
|
A neonate who is brought for evaluation due to vomiting and jaundice is found to be icteric, edematous, and to have hepatomegaly and cataracts. Labs demonstrate low serum glucose; ALT, AST, & direct bilirubin. What is the defect responsible for this infant’s problems?
A. glucocerebrosidase deficiency B. hexosaminidase A C. galactose-1-phosphate uridyl transferase deficiency D. insulin deficiency E. phenylalanine hydroxylase deficiency |
C. galactose-1-phosphate uridyl transferase deficiency. results in the inability to metabolize galactose, causing hi galactose levels. It is galactosemia. If uncontrolled, it leads to cataracts.Other manifestations from the hi galactose levels are hypoglycemia, hepatomegaly, and hi liver enzymes, and cataracts in babies of uncontrolled mothers.
|
|
|
glucocerebrosidase deficiency
|
causes accumulation of glucocerebroside, causing hepatosplenomegaly, erosion of long bones via osteoporosis, MR, and, usually, death. This is Gaucher's disease.
|
|
|
hexosaminidase A
|
Tay-Sachs disease and causes the accumulation of ganglioside GM2 and causes MR, a cherry red macula with blindness, seizures, and muscular weakness.
|
|
|
A 48 year old female is brought to the ER after being found unconscious in her home. She apparently had accidentally left her car running in the below-level garage. On physical exam, she demonstrates red skin with cherry red lips and increased DTRs. She regains consciousness after administration of 100% O2. She complains of headache. What is a true statement regarding the offending agent?
A. it has a greater affinity for hemoglobin than does O2 B. it has a lower affinity for hemoglobin than does O2 C. it has greater affinity for HbA than it does for HbF D. it has greater affinity for O2 than CO2 E. it has no relationship with hemoglobin |
A. it has a greater affinity for hemoglobin than does O2
|
|
|
An alcoholic patient is admitted to the hospital for hypoglycemia. The first therapy he receives is a 5% glucose in saline solution. Several days later he develops ataxia, ophthalmoplegia and confusion. What vitamin deficiency is responsible for this patient’s more recent problems?
A. folic acid B. vitamin B12 C. vitamin B3 D. Vitamin B2 E. vitamin B1 |
E. vitamin B1 - This patient is suffering from Wernicke's encephalopathy:ataxia, ophthalmoplegia, and confusion. It is a profound, acute-onset thiamine (B1) deficiency common to alcoholics who suddenly have their metabolism "jump-started" by IV glucose. Prevention is key, and is comprised of B1 administration prior to IV glucose administration.
|
|
|
A Jewish child with a past medical history of mental retardation and multiple bone fractures with minimal trauma is weak and easily bruises. He presents for an annual physical exam. Physical exam reveals hepatomegaly and splenomegaly. Fundoscopic exam is normal. Spine X-ray demonstrates biconcave vertebral bodies. What is the most likely diagnosis?
A. osteogenesis imperfecta B. Niemann-Pick Disease C. Gaucher’s Disease D. Albers Schonberg Disease E. Phenylketonuria |
C. Gaucher’s Disease. Gaucher's disease is marked by severe osteoporosis, leading to multiple fractures. Over time, the vertebral bodies also become biconcave. Other features of the disease are mental retardation, hepatomegaly, and splenomegaly. It is a sphingolipidosis caused by the deficiency of beta-glucosidase (glucocerebrosidase).
|
|
|
Albers Schonberg disease results in ?
|
sclerotic changes of the vertebral bodies, yielding vertebrae that look like "Rugger Jersey"s. It is also called osteopetrosis or marble bone disease.
|
|
|
A 30-year-old black male presents with acute, severe pain in his right lower extremity. He has had similar previous episodes throughout his life in other parts of his body. Physical exam reveals fever and a right lower extremity which is erythematous and edematous in the upper lateral region; it is acutely painful to palpation. What hemoglobin is responsible?
A. Hb F2 B. Hb A1C C. Hb A2 D. Hb C E. HB S |
E. HB S
Hemoglobin S is the hemoglobin of sickle cell disease, the disease from which this patient suffers. This hemoglobin contains beta-globins in which valine has replaced glutamic acid at the 6th residue position. |
|
|
a mutation at the same site as Hbg S, except that lysine (not valine) replaces glutamate and no tendency to distort the shape of the RBC as Hb S does.
|
Hb C
|
|
|
A 42-year-old white female presents with complaints of polyuria and polydypsia. Fasting serum glucose levels are inconclusive. Labs demonstrate low urine specific gravity and osmolarity. What is the most likely diagnosis?
A. Diabetes mellitus B. Diabetes insipidus C. Cushing’s syndrome D. Conn’s syndrome E. Renal artery stenosis |
B. Diabetes insipidus. Polyuria, polydipsia,& lo urine specific gravity & osmolarity (e.g.,dilute urine) are findings for diabetes insipidus. DI results in poor water reabsorption at the collecting duct, causing the loss of volumes of water.There are 2 types of DI: nephrogenic and central. The nephrogenic form is due to the kidney's inability to respond to ADH(antidiuretic hormone), the molecule responsible for activating water reabsorption (with no electrolytes) in the collecting duct. The central form is due to the posterior pituitary gland's inability to make ADH.
|
|
|
presents with polyuria and polydipsia. But, serum glucose levels will be high, and urine specific gravity and osmolarity will be normal to high due to glucose in the urine.
|
diabetes mellitus
|
|
|
A 4-month-old infant is brought by his mother for evaluation for recurrent bouts of vomiting, tremors, and lethargy. The baby was healthy while being exclusively breastfed. However, he has had intermittent occurrences since his diet was expanded. The mother relates that she thinks his symptoms seem to have some relationship to consuming fruit juices and sweets. What enzyme is likely deficient in this child?
A. aldolase B B. glucose-6-phosphatase C. insulin D. cystathionine synthetase E. fructokinase |
A. aldolase B
Aldolase B is fructose 1-phosphate aldolase, and a deficiency of it results in an accumulation of fructose 1-phosphate. The deficiency causes hypoglycemia, fructosemia, fructosuria, and hepatic injury; the disease entity is known as fructose intolerance, and does not manifest until the child's diet is expanded to include fructose-containing foods. |
|
|
glucose-6-phosphatase deficiency?
|
a deficiency of glucose-6-phosphatase results in Von Gierke's disease, a disorder characterized by hypoglycemia. It is clinically evident from birth onward.
|
|
|
A 29-year-old Asian male is the victim of a motor vehicle accident in which he sustains a massive crushing injury to his lower extremities bilaterally. By day two of his hospital stay, he starts to produce reddish-brown urine. Serum labs show elevated BUN, creatinine, potassium, phosphate, and CPK. What is causing the elevated BUN, creatinine, potassium, and phosphate?
A. post-renal acute renal failure due to sudden onset development of uric acid stones B. pre-renal acute renal failure due to hemorrhage C. intra-renal acute renal failure due to a renal crush injury D. acute tubular necrosis due to myoglobin E. acute tubular necrosis due to proteins in urine filtrate |
D. acute tubular necrosis due to myoglobin. Massive crush injuries of skeletal muscle cause large amts of myoglobin to be released into the bloodstream and ultimately across the glomeruli to enter the renal tubules where it causes acute tubular injury. This injury may result in necrosis of renal tubular cells, causing acute tubular necrosis. Thus, excess myoglobin, a reddish-brown molecule, causes acute renal failure (ARF) that is renal or intrinsic. ARF is marked by hi BUN, creatinine, potassium, and phosphate.
|
|
|
A 20 year-old white female presents with abdominal pain and vomiting. Her baby daughter was murdered just hours earlier; the patient has been very distraught and has refused any food or water. She has a past medical history significant for type I DM. Her vitals include a HR of 99, and BP of 85/40. Physical exam reveals Kussmaul's respiration, dehydration, and fruity odor on the breath. Labs demonstrate hyperglycemia. What pH finding is expected and what is the cause of the finding?
A. normal; dehydration B. acidemia; glucose C. acidemia; ketone bodies D. alkalemia; bicarbonate E. alkalemia; Kussmaul's respiration |
C. acidemia; ketone bodies.
|
