Q-Bank- Biochemistry

Front 1

Describe the rate limiting step in catecholamine synthesis.

Back 1

The conversion of Tyrosine to Dopa by Tyrosine Hydroxylase is the rate limiting step of Catecholamine synthesis.

Front 2

During periods of stress what enzyme involved in catecholamine synthesis is upregulated? Is this enzyme in the catecholamine storage vessicle or out in the cytoplasm?

Back 2

PNMT which makes Epinephrine from Norepinephrine. This enzyme exists in the cytoplasm where this conversion takes place.

Front 3

Which enzyme acts on dopamine as it enters the catecholamine vessicle? What is it changed into?

Back 3

Dopamin-Beta-hydroxylase acts on Dopamine as it enters the catecholamine storage vessicle and is converted into Norepinephrine.

Front 4

What is LCAD deficiency and what are its associated symptoms?

Back 4

This is a deficiency of the enzyme Long Chain Acyl CoA dehydrogenase. LCAD affects the first step in B-oxidation of fatty acids in the mitochondria. Muscle weakness, eventual cardiomyopathy, resting hypoglycemia and hypoketosis are all symptoms that present early in childhood. Death is common.

Front 5

Describe the enzyme deficiency seen in Hurler disease. What class of genetic disorder is this? Explain the associated symptoms.

Back 5

Hurler disease is a lysosomal storage disease associated with a deficiency of alpha-L-iduronidase. Cardiomyopathy, valvular disease, and potential coronary artery occlusion are results of specific glycosaminoglycan (heparan and dermatan sulfate) accumulation. This accumulation results in corneal clouding, mental retardation, and skeletal abnormalities.

Front 6

Describe the enzyme deficiency seen in Pompe disease. What class of genetic disorder is this? What organ systems are most affected?

Back 6

Pompe disease is a lysosomal storage disease resulting from a deficiency of Acid Maltase (alpha-1,4 glucosidase). In this disease glycogen fragments accumulate in lysosomes and primarily affect organs responsible for glycogen storage (Liver, Muscle, Kidney)

Front 7

Describe the enzyme deficiency seen in McArdle disease. Describe what would be seen in a muscle biopsy of this patient.

Back 7

McArdle disease is a muscle glycogen phosphorylase deficiency disease. This is associated with muscle weakness and potential cardiomyopathy. A muscle biopsy of a patient with muscle glycogen phosphorylase deficiency would reveal glycogen deposits.

Front 8

Which forms of Glycogen Phosphorylase (GP) and Glycogen Synthase (GS) are active? Do Glucagon and Insulin activate protein kinases or phosphorylases?

Back 8

The phosphorylated form of Glycogen phosphorylase is active. The other one is the other one. Glucagon activates a Protein kinase that phosphorylates GP, while insulin activates a phosphorylase that dephosphorylates GS.

Front 9

What role does Gamma-Carboxylation play with respect to blood clotting?

Back 9

Gamma-carboxylation produces sites that bind calcium and is particularly common among blood clotting factors.

Front 10

What is one of the main mechanisms by which the cell directs proteins to particular locations?

Back 10

Glycosylation is the chemical enzymatic linkage of oligosaccharides to proteins as they pass through the ER and Golgi apparatus, and is often the mechanism by which cells direct proteins to particular destinations

Front 11

What is the job of Pyruvate dehydrogenase? What are the cofactors it uses?

Back 11

Pyruvate dehydrogenase converts pyruvate to acetyl coenzyme A. The cofactors that pyruvate dehydrogenase uses are TPP, lipoic acid, CoA, FAD + and NAD +

Front 12

TPP (thiamine pyrophosphate) comes from the water soluble vitamin Thiamine. What two pathways that breakdown carbohydrate, use TPP?

Back 12

Krebs cycle (Pyruvate dehydrogenase); Pentose Phosphate Pathway (Transketolase).

Front 13

What is the job of Lactate dehydrogenase?

Back 13

Lactate dehydrogenase produces lactate from pyruvate.

Front 14

What is the job of Pyruvate Kinase? Why is it a misnomer?

Back 14

Pyruvate kinase produces Pyruvate from Phosphoenolpyruvate by dephosphorylation. It is a misnomer because kinases usually phosphorylate things, but this one is dephosphorylating and doesn't even act on Pyruvate, it creates it.

Front 15

What pathway is transketolase involved in? Describe the job that it does. What cofactor does it use?

Back 15

Transketolase is involved in the Pentose Phosphate Pathway. It uses the cofactor Thiamine Pyrophosphate (TPP), and accepts a 2-carbon fragment from a 5-carbon ketose (D-Xylulose-5-P), then transfers this fragment to a 5-carbon aldose (D-Ribose-5-P) to form a 7-carbon ketose (Sedoheptulose-7-P)

Front 16

Describe the problem in Fructose-1-Phosphate Aldolase Deficiency. What is the pathogenesis of this disease and how old are patients when they present?

Back 16

Fructose-1-Phosphate Aldolase Deficiency is an autosomal recessive disorder due to deficient F1P aldolase deficiency. This results in an accumulation of F1P and this inhibits glycogenolysis and gluconeogenesis. This in turn causes severe hypoglycemia following ingestion of fructose. Prolonged fructose ingestion in infants ultimately leads to hepatic failure and death. This is known as fructose intolerance.

Front 17

Describe essential fructosuria. Is this fatal?

Back 17

Essential fructosuria involves a defect in Fructokinase and is a benign asymptomatic condition.

Front 18

What reaction does Hexokinase catalyze?

Back 18

Hexokinase catalyzes the first step in glycolysis.

Front 19

Monosodium urate, needle shaped, strongly negative birefringent crystal are associated with what disease?

Back 19

Gout.

Front 20

What is the compound that precipitates to create crystals in CPPD crystal deposition disease/"pseudogout"?

Back 20

Calcium Pyrophosphate Dihydrate crystals are associated with CPPD crystal deposition disease (aka Pseudogout). Features of these crystals include rod-to-rhombiod shapes and weakly positively birefringent crystals (opposite to those seen in Gout).

Front 21

What disease are Basic Calcium Phosphate crystals associated with?

Back 21

Basic Calcium Phosphate crystals are seen in Apatite-Associated Arthropathy and produces spherical clumps of non-brefringent submicroscopic crystals.

Front 22

Decribe the appearance and associated disease of each of these crystals:
1) Monosodium Urate Crystals

2) Calcium Pyrophosphate Dihydrate Crystals

3) Basic Calcium Phosphate Crystals

Back 22

1) Monosodium Urate crystals are needle-shaped, strongly negatively biregfringent crystals associated with Gout

2) Calcium Pyrophosphate Dihydrate crystals are rod-to-rhombiod shaped, weakly positively birefringent cystals associated with CPPD/Pseudogout disease.

3) Basic Calcium Phosphate Crystals produces spherical clumps of non-brefringent submicroscopic crystals associated with Apatite-Associated Arthropathy.

Front 23

Lack of Thyroid Hormone during fetal development leads to what condition? What are some associated signs and symptoms? How does lack of TH this develop?

Back 23

Lack of Thyroid hormone in fetal development leads to a disorder called Cretinism. Some of the signs of cretinism include severe mental retardation, pale skin, pot-bellied appearance and a puffy face. There is also enlargement of the tongue. This lack TH could be due to dietary deficiency of iodine, to developmental failure of thyroid formation, or to a defect in thyroxine synthesis.

Front 24

Describe the pathophysiological mechanism of Cretinism and bone formation?

Back 24

Cretinism is due to a lack of Thyroid Hormone during fetal development. Untreated cretinism results in a form of dwarfism. TH appears to be permissive or act synergistically with growth hormone or growth factors acting directly on bone. In fact, thyroid hormone is required for normal synthesis and secretion of growth hormone.

Front 25

What type of disorder should hepatosplenomegaly accompanied by neurological degeneration make you think of?

Back 25

This should make you think of lysosomal storage diseases.

Front 26

Describe the pathogenesis of Niemann-Pick disease? What is a featured symptom that it shares with a disease prominent amongst Ashkenazi Jews?

Back 26

Niemann-Pick is a lysosomal storage disease due to a deficiency of sphingomyelinase, which leads to an accumulation of sphingomyelin. It generally results in death by age two. The sign it shares is a Cherry-red spot that is also associated with Tay-Sachs, associated hepatosplenomegally suggests Niemann-Pick rather than Tay Sachs.

Front 27

Describe the pathogenesis of Hunter syndrome. Describe some of teh symptoms. What is a closely associated disease and how can you distinguish between the two?

Back 27

Hunter syndrome is a mucopolysaccharidosis inherited in an X-linked recessive fashion. Iduronate Sulfatase is deficient, and symptoms include hepatosplenomegaly, kyphosis, flexion contractures, short stature, valvular and ishemic heart disease, and congestive heart failure. ***Notably there are not corneal opacities, which differentiates it from the similar condition Hurler Syndrome.

Front 28

What disease is caused by a deficiency of N-acetylglucosamine-1-phosphotransferase? Describe the pathophysiology of the disease that is produced.

Back 28

This disease is called I-CELL disease. N-acetylglucosamine-1-phosphotransferase is an enzyme that is essential for targeting lysosomal enzyme from the Golgi to lysosomes. The deficiency results in accumulation of undigested substrates in lysosomes and abnormally high activity of these enzymes in the extracellular space.

Front 29

Name the disease that is associated with a deficiency of Glucose-6-Phosphatase. Describe associated organ and clinical features.

Back 29

This is Von Gierke disease. It is a severe form of glycogen storage disease that is characterized by hypoglycemia, hepatomegaly, and renomegaly. Clinical features include sever hypoglycemia, lactic acidosis, hyperlipidemia, hyperuricemia and short stature.

Front 30

Describe the typical presentation of from a patient that suffers from a glycogen storage disease. What organ in particular is usually invovled? Which form of glycogen storage disease is restricted to skeletal muscle?

Back 30

There are a variety of glycogen storage diseases corresponding to different defects in glycogen metabolism, but most present with complaints of severe muscle cramps and weakness with moderate exercise, with some individuals experiencing myoglobinuria. Most of these diseases involve the liver. McArdle disease, due to a defect in muscle glycogen phosphorylase (myophosphorylase), is restricted to sekeltal muscle.

Front 31

What autosomal recessive disorder is characterized by defective neutral amino acid transport in the small intestine and kidneys? Describe some associated symptoms.

Back 31

Defective amino acid transport in the small intestine and kidneys is typical of Hartnup disease. Patients with Hartnup disease present wtih pellagra like-skin eruptions, cerebellar ataxia, aminoaciduria.

Front 32

What class of disease is Krabbe disease a part of? Describe the pathophysiology. How is it transmitted? Describe some of the signs and symptoms.

Back 32

Krabbe disease is a lysosomal storage disease. This results from galactocerebroside-galactosidase deficiency that affects the myelin sheaths of the central nervous system. Some of the signs and symptoms associated with Krabbe disease include hypertonia, irritability, hyperesthesia, psychomotor retardation and early death. Krabbe is transmitted in an autosomal recessive pattern.

Front 33

What is the first this that occurs in the processing of mRNA? Does this happen during or post-transcription? What is the purpose of this step?

Back 33

The first that happens in the processing of the mRNA is the addition of a 7-methylguanosine triphosphate 5' end cap. This happens DURING transcription and will serve to provide the binding energy of the mRNA transcript to the ribosome during the initiation of translation.

Front 34

What purpose does the polyadenylate tail added to the end of mRNA transcripts serve?

Back 34

This polyadenylation protects against degredation and aids in transport to the cytoplasm.

Front 35

In mRNA processing are Introns or Exons removed and degraded? How is this done? What splices them?

Back 35

The Introns are removed and degraded as lariat structures, by Spliceosomes. After their removal they are degraded.

Front 36

What acute event lasting 7-10 days can spur pain crises in patients with sickle cell disease? What are the symptoms associated?

Back 36

Viral infection. This can result in arthralgia and sometimes abdominal pain with vomiting.

Front 37

What is a common treatment of homozygotes with sickle-cell disease?

Back 37

Hydroxyurea treatment is common for homozygotes with sickle-cell disease.

Front 38

Describe the enzyme that is deficient in Aldolase B deficiency. Who is affected: adults or infants? What is the job of this enzyme (what other enzyme does it hydrolyze other than its name-sake, that is responsible for the toxicity of this disease)?

Back 38

Aldolase -B-deficiency is a sever condition affecting infants in which there is a deficiency of the enzyme Fructose-1,6-bisphosphate aldolase. This enzyme is responsible for catalyzing the hydrolysis of F-1,6,-BP into triose phosphate and glyceraldehyde phosphate. It also hyrolyzes Fructose-1-phosphate.

Front 39

Which organs does the deficiency of Fructose-1,6-bisphosphate aldoase affect? What is the name of this disease? Describe the pathophysiology of this diseasewhat other enzyme does it hydrolyze other than its name-sake, that is responsible for the toxicity of this disease).

Back 39

The absence of F-1,6-BP affects the liver, kindeys and intestine. The name of this disease is Aldolase B deficiency. With this deficiency there is a rapid accumulation of Fructose-1-phosphate and severe toxicity when exposed to fructose.

Front 40

What is the job of Galactokinase? A deficiency of this enzyme leads to what disease?

Back 40

Galactokinase catalyzes the phosphorylation of galactose. With a deficiency of this enzyme there is an accumulation of galactose and galactitol and CATARACTS are usually the sole manifestation.

Front 41

Galactose-1-phosphatase deficiency leads to toxicity caused by what molecule? Are adults or infants affected? What are organs are involved?

Back 41

Galactose-1-phosphatase deficiency results in classic galactosemia from the inability to metabolize galactose-1-phosphate. This molecule accumulates in infants and causes injury to the kindeys, liver, and brain, and without treatment the infant will die. This process may begin prenatally due to transplacental transport of galactose.

Front 42

Describe the enzyme deficiency in Von Gierke disease and what clinical signs and symptoms it leads to. Does this deficiency affect adults or infants?

Back 42

In Von Gierke disease there is a deficiency of the enzyme Glucose-6-phosphatase, which manifests as a Type 1a liver glycogenosis (glycogen storage disease). Here there is inadequate hepatic conversion of glucose-6-phosphate to glucose and the patient is susceptible to fasting hypoglycemia. Patients present at 3-4 months of age with hypoglycemic seziures. Associated clinical findings of growth retardation, increased serum lactate, increased cholesterol, increased triglycerides, and massive hepatosplenomegaly and kidney enlargement.

Front 43

Explain the gene defect associated with Marfan syndrome. Production of what molecule is affected? What signs and symptoms does this result in?

Back 43

Marfan syndrome is an autosomal disorder caused by a gene defect on chromosome 15 encoding Fibrillin. Fibrillin is a major component of elastin associated Microfibrils. Abnormal Fibrillin production predisposes for cystic medial necrosis of the aorta, which may be complicated by aortic dissection. Other features of the syndrome are subluxation of the lens of the eye, mitral valve prolapse, and a shortened life span (often due to aortic rupture).

Front 44

What are microfibrils and what genetic disorder is associated with a defect in the Firbrillin gene on Chromosome 15?

Back 44

Microfibrils are ubiquitous matrix polymers that are thought to to provide elastic properties in all extracellular matrix structures. Marfan's syndrome is associated with a defect in the Fibrillin gene on Chromosome 15.

Front 45

Diseases affecting Microtubule formation affects what type of structures and cellular processes in the body?

Back 45

Defects in microtubule synthesis affect processes such as intracellullar transport, such as the transport of chromosomes during mitosis and meiosis, as well as motility produced by cilia or flagella.

Front 46

Which is the more specific technique to detect specific proteins: ELISA or Western blot?

Back 46

The most specific test to detect proteins is Western Blotting. This can confirm reactivity as well as molecular weight. ELISA can also detect specific proteins, but since the proteins are not separated by molecular weight, ELISA is less specific. ELISA is used as a screening test and often has many false-negatives and false-positives.

Front 47

What is the most common Urea Cycle disorder? Briefly explain the pathophysiology of this disorder.

Back 47

Orinithine transcarbamylase (OTC) deficiency is the most common of the urea cycle disorders. This is a genetic disorder resulting in a mutated and ineffective form of the enzyme Ornithine transcarbamylase. Like other urea cycle disorders, OTC deficiency affects the body's ability to eliminate ammonia, a toxic by-product of the body's use of protein. Hyperammonemia allows ammonia to travel to various organs of the body, including the brain where it can cause coma, brain damage and death.

Front 48

What are the main criterion for the diagnosis of urea cycle?

Back 48

The main criterion for the diagnosis of urea cycle defects is hyperammonemia.

Front 49

Compare and contrast patients with Orinthine transcarbamylase (OTC) deficiency from patients with Carbamoyl phosphate synthetase deficiency (CPS).

Back 49

Both OTC and CPS have no abnormalities of plasma amino acids, except for increased levels of glutamine secondary to the hyperammonemia. In OTC, however, there is a marked increase in urinary excretion of Orotic acid that is not seen in CPS.

Front 50

Patients with deficiencies of Argininosuccinic acid synthetase, Argininosuccinic acid lyase, or arginase have increases in plasma levels of what Urea cycle metabolites?

Back 50

They have marked increases in plasma levels of of Citruline, Argininosuccinic acid, and Arginine, respectively.

Front 51

In the Urea cycle, what molecule is used to remove NH4 from the Mitochondrial matrix? What molecule is recycled and brought back into the Mitochondrial matrix to start the cycle over again?

Back 51

Citrulline is the molecule that is used to shuttle NH4 out of the mitochondrial matrix. After two reactions in the cytoplasm to produce Arginine, Urea is removed from the Arginine and Ornithine is created. Ornithine goes back into the mitochondrial matrix and is used to replenish the cycle and help recreate Citrulline, after it combines with Carbamoyl phosphate.

Front 52

Name four reasons why an alcoholic might have a bleeding disorder.

Back 52

Alcoholic patients have many reasons to bleed. If there is liver damage they could have a coagulopathy from failure to make clotting factors or a vitamin K deficiency. They may also have decreased platelets from hypersplenism or Scurvy (Vitamin C deficiency).

Front 53

Explain the pathophysiology of Scurvy. How does the disease present clinically?

Back 53

Absence of Vitamin C leads to impaired hydroxylation of proline residues in nascent procollagen chains, leading to weakness of blood vessel walls. Clinically, the deficiency syndrome is characterized by perifollicular hemorrhages, fragmentation of hairs, purpura, ecchymoses, splinter hemorrhages, and hemorrhages into muscle. In patients with normal dentition, gum changes (swelling and bleeding of the gums, and loosening of the teeth) are also noted. Without vitamin C supplementation, death may eventually occur.

Front 54

What are the problems caused by Thiamin (Vitamin B1 deficiency)?

Back 54

Wernike neuropathy, Kosakoff psychosis, and potentially, congestive heart failure.

Front 55

What vitamin deficiency causes Wernike-Korsakoff syndrome?

Back 55

Vitamin B1 deficiency.

Front 56

What is the vitamin deficiency that causes microcytic sideroblastic anemia?

Back 56

Pyridoxine (Vitamin B6) deficiency.

Front 57

Pryidoxine (Vitamin B6) deficiency can cause what type of anemia?

Back 57

A deficiency of Pyridoxine (Vitamin B6) can cause microcytic sideroblastic anemia.

Front 58

A deficiency of which B vitamin can cause megaloblastic anemia and potentially lead to progressive neuropathy?

Back 58

Cobalamin (Vitamin B12).

Front 59

Vitamin B12 deficiency can lead to what conditions?

Back 59

Vitamin B12 (Cobalamin) deficiency can lead to megaloblastic anemia and potentially a peripheral and progressive neuropathy.

Front 60

What are the enzymes that require Thiamine (Vitamin B1) to function?

Back 60

Pyruvate Dehydrogenase (PDH), Alpha-ketoglutarate Dehydrogenase (AKDH), and Transketolase.

Front 61

What are the metabolic pathways that require Thiamine (Vitamin B1) to progress?

Back 61

PDH pathway taking pyruvate to acetyl-CoA (PDH), TCA cycle (Alpha-KDH), HMP shunt (Pentosphosphate pathway)(Transketolase)

Front 62

Describe the most common way to acquire a Thiamine (Vitamin B1) deficiency, what the names of the associated syndromes are called, and what some of the symptoms of those syndromes are.

Back 62

Thamine deficiency is most often caused by alcohol interference with its absorption. It causes Wernike-Korsakoff syndrome which consists of Wernike neuropathy (ataxia, nystagmus, opthalmopelgia), Korsakoff psychosis (confabulation, psychosis), and Wet Beri-Beri (high output cardiac failure).

Front 63

What are the enzymes that need Pyridoxine (Vitamin B6) to function?

Back 63

Aminotransferases, and Aminolevulinate synthase.

Front 64

Name the metabolic pathways that require Pyridoxine (Vitamin B6).

Back 64

Protein catabolism, and Heme synthesis.

Front 65

What are the causes of Pryidoxine (Vitamin B6) deficiency and what are the clinical conditions/symptoms it can cause?

Back 65

Pyridoxine (Vitamin B6) deficiency is caused by isoniazide (INH) therapy. It can lead to sideroblastic anemia due to a lack of heme synthesis, and can also cause convulsions.

Front 66

What are the enzymes that require Cobalamin (Vitamin B12) to function?

Back 66

Homocysteine methyltransferase, and Methyl-Malonyl-CoA mutase.

Front 67

What are the metabolic pathways that require Cobalamin (Vitamin B12)?

Back 67

Methionine, SAM (S-adenosyl methionine), Odd carbon fatty acids, Val, Met, Ile, Thr.

Front 68

What causes Cobalamin (Vitamin B12) deficiency? What type of conditions can Cobalamin deficiency cause?

Back 68

Cobalamin deficiency is caused by pernicious anemia, aging, poor nutrition, bacterial overgrowth in the terminal ileum, ileal resection, chronic pancreatitis, and rarely vegans or infection with Diphyloborthrium latum. Megaloblastic anemia, and progressive peripheral neuropathy are both conditions that are caused from Cobalamin (Vitamin B12) deficiency

Front 69

What enzymes require Ascorbate (Vitamin C) in order to function?

Back 69

Prolyl and lysyl hydroxylases, and Dopamine beta-hydroxylase.

Front 70

The synthesis of what molecule requires Ascorbate (Vitamin C)?

Back 70

Collagen synthesis requires Ascorrbate (Vitamin C).

Front 71

What are some of the symptoms associated with Scurvy (Vitamin C deficiency)?

Back 71

Some of the symptoms that are associated with scurvy are poor wound healing, easy bruising, perifolicular hemorrhage, bleeding gums, painful glossitis, annd anemia.

Front 72

Becker muscular dystrophy (BMD) and Duchenne muscular dystrophy(DMD) are known to be encoded by mutations at the same locus, yet BMD has a much slower clinical progression. Why?

Back 72

This is because in BMD there is an in-frame deletion or insertion that produces and altered protein product (dystrophin) with slightly different properties, but there is still a protein product produced. In DMD, there is a frame-shift mutation that results in a truncated protein due to the creation of early stop codons. The truncated protein is degraded, resulting in complete absence of any protein altogether.

Front 73

Which type of muscular dystrophy is more severe and why: Becker muscular dystrophy or Duchenne musclar dystrophy?

Back 73

Duchenne muscular dystrophy is more severe because it involves a frameshift mutation in the dystrophin gene, whereas Becker muscular dystophy involves in-frame mutations or insertions.

Front 74

What is the mode of inheritance of both Becker and Duchenne muscular dystrophy?

Back 74

X-linked recessive mutation.

Front 75

Hepatomegaly, cardiomegaly, and heart failure secondary to cardiomyopathy are all characteristic features of what metabolic disease. Describe the pathophysiology of this disease. What enzyme is involved?

Back 75

These are all characteristic features of Pompe disease. This is one of the glycogen storage diseases. In this condition, glycogen accumulates in all organs due to a deficiency of Lysosomal Alpha Glucosidase.

Front 76

What separates Pompe apart from disease from other glycogen storage diseases (notably Von Gierke disease).

Back 76

Pompe disease is set apart from other glycogen storage diseases, and in particular from Von Gierke disesase, by the relative prominance of skeletal and cardiac muscle symptoms (weakness) and the realtive lack of hypoglycemia and acidotic episodes.

Front 77

What class of disease is Pompe disease? What is the enzyme deficiency causing Pompe disease?

Back 77

Pompe disease is a Glycogen storage disease. Pompe is due to a deficiency of Lysosomal Alpha Glucosidase.

Front 78

What class of disease is Von Gierke disease? What is the enzyme deficiency that characterizes Von Gierke disease? Describe the clinical findings associated with Von Gierke.

Back 78

Von Gierke is a Glycogen storage disease. It is caused by a deficiency of Glucose-6-Phosphatase and is characterized by severe hypoglycemia, lactic acidosis, hepatomegaly, renomegaly, hyperlipidemia, and hyperuricemia.

Front 79

What class of disease is Andersen disease? What enzyme deficiency characterizes Andersen disease? Descirbe some of its clinical findings.

Back 79

Andersen disease is a Glycogen storage disease and is characterized by Branching Enzyme deficiency. Clinical findings that are associated are hypotonia, cirrhosis, and early death (by age 2).

Front 80

McArdle disease involves what enzyme deficiency? What class of disease is this? Describe some of the clinical findings associated with this disease (*think McArdle sports equipment).

Back 80

McArdle's disease is due to a deficiency of Myophosphorylase and is considered a Glycogen storage disease. It presents with muscle cramps and weakness on exercise.

Front 81

Niemann-Pick disease results from a deficiency of what enzyme? What class of disease is this? Describe some of the clinical findings.

Back 81

Niemann-Pick disease results from a Sphingomyelinase deficiency. This is a Lysosomal Storage Disease due to a disorder of sphingolipid catabolism characterized by hepatosplenomegaly, microcephaly, severe mental retardation, zebra bodies in inclusions, characteristic foamy macrophages, and early death.

Front 82

What two diseases should you associate with people of Ashkenazi Jewish descent? What class of disease are they? Which is a more severe disease?

Back 82

You should associate Ashkenazi Jews with Tay-Sachs disease and Type I gaucher's disease. Both of these diseasea are sphingolipidoses. Tay-Sachs is the more devastating of the two, and is characterized by progressive neurological (including visual) deterioration beginning at about 6 months of age and leading to death by age 3.

Front 83

Branched chain amino acid disease (maple syrup urine disease) is due to a deficiency of what enzyme? Catabolism of which amino acids is affected?

Back 83

The defective enzyme in this disease branched-chain ketoacid dehydrogenase. This is normally involved in the catabolism of brancehed-chain amino acids that have been previously transaminated to form their ketacid derivatives. The catabolism of Leucine, Isoleucine, and Valine is impaired and should thus be eliminated from or minimized in the diet.

Front 84

Histidinemia is due to a deficiency in what enzyme? Is this disease serious?

Back 84

Histidinemia is due to a deficiency in the enzyme histidine decarboxylase which leads to an accumulation of histidine. This disease is not serious and most patients are asymptomatic.

Front 85

Abnormal methionine metabolism is involved in what two diseases?

Back 85

Homocystinuria and Cystathionuria.

Front 86

What is enzyme deficiency is classic Homocystinuria caused by? What are the increased risks for other disease associated with someone who has Homocystinuria?

Back 86

Classic homocystinuria is caused by a deficiency in cystathionine synthase. Homocystinuria is associated with increased risk of atherosclerosis, stroke, deep vein thrombosis, disociated lens and mental retardation.

Front 87

What problems does a deficiency in homosysteine methyltransferase (not classically associated with homocystinuria) lead to?

Back 87

Homocysteine methyltransferase deficiency leads to megaloblastic anemia and mental retardation.

Front 88

Homocystinuria can be caused by a deficiency in what vitamins? What condition does this put someone at risk for developing?

Back 88

Deficiency in Folate, Pyrioxine (Vitamin B6), or Vitamin B12 can lead to mild homocystinuria and increased risk of atherolsclerosis.

Front 89

You should associated abnormal metabolism of what amino acid with ablinism? What are the enzyme deficiencies that cause this abnormal metabolism and albinism? Why? What type of cancer is a person with this condition at risk for?

Back 89

Associate abnormal Tyrosine metabolism with albinism, where congenital deficiency of Tyrosinase or a Tyrosine transporter leads to reduced pigmentation of the skin, eyes, and hair (reduced melanin), which increased the risk of skin cancer.

Front 90

What is the error of amino acid metabolism associated with Alkaptonuria? What is the enzyme deficiency?

Back 90

Abnormal Tyrosine metabolism is part of Alkaptonuria, which is due to an accumulation of homogentisic acid due to a deficiency in homogentisate oxidase.

Front 91

Alzheimer disease presents with deposition of what type of plaques?

Back 91

Beta-amyloid plaques.

Front 92

Do patients with Hereditary Nonpolyposis Colorectal Cancer still develop colorectal polyps? What genetic defects do they display?

Back 92

Yes, patients with HNPCC can develop colorectal polyps over their lifetime, and the probability of malignant transformation in these patients is greatly increased. Patients with HNPCC also show an increased incidence of brain, endometrial, gastic and thryroid cancers. These patients with Type I HNPCC have been found to display microsatellite instability and deficieny mismatch repair genes.

Front 93

Carnitine is a derviative of what amino acid? Which enzyme requires Carnitine? What is the main function of Carnitine?

Back 93

Carnitine is a derivative of the amino acid lysine. It is used in the enzyme carnitine palmitoyltransferase, which is required in order to transport long-chain fatty acids into the mitochondria.

Front 94

Describe the symptoms of Carnitine deficiency.

Back 94

Symptoms of Carnitine deficiency include persistent hypoglycemia, hyperammonemia, skeletal muscle weakness, and myglobinuria. Carnitine deficiency may also cause fatty liver, lipid storage myopathy, and confusion.

Front 95

What is needed to import nascent proteins into the llumen of the rough ER?

Back 95

An N-terminal hydrophobic signal sequence is required to import proteins into the lumen of the rough ER.

Front 96

What molecule is necessary for targeting misfolded proteins to proteosomes?

Back 96

Targeting misfolded proteins to proteasomes requires Ubiquitin.

Front 97

What special carbohydrate addition is necessary to transfer digestive proteins from the Golgi apparatus to Lysosomes?

Back 97

Phosphorylation of Mannose (mannose-P) attached to digestive enzymes is required for those enzymes to be transfered to the lysosomes.

Front 98

Would serum Alanine levels be expected to rise or fall during starvation?

Back 98

Serum alanine levels would be expected to drop dramatically in the starvation state.

Front 99

Would serum Bicarbonate levels be expected to rise or fall during the starvation state?

Back 99

Bicarbonate levels drop as the bicarbonate buffers the hydrogen ions produced by the ketone bodies during the starvation state.

Front 100

Where does the production of ketone bodies come from during the starvation state?

Back 100

During starvation fatty acids are released into the blood and delivered to the liver, adipose tissue, and muscle where they are broken down via Beta Oxidation. This produces Acetyl-CoA, which accumulates in the liver and is used for ketone body synthesis.

Front 101

During the starvation state, which tissues use ketone bodies for energy and which do not?

Back 101

During the starvation state, ketones will be metabolized in muscle and, after a week of starvation, in the brain. This spares glucose for tissues relying on anaerobic glycolysis (RBCs) and also, importantly, slows the breakdown of essential body protein.

Front 102

What are the two types of ketone bodies derived from fatty-acid breakdown that the body uses for fuel during the starvation state?

Back 102

Acetoacetic acid, and 3-hydroxybutyric acid.

Front 103

What types of molecules can be used for gluconeogenesis by the body in times of need?

Back 103

Glucose cannot be synthesized from most fatty acids (odd-carbon fatty acids being a minor exception), and is instead made from amino acids such as alanine, and other molecules like glycerol-3-phosphate, and lactate (from anaerobic metabolism) during the process of gluconeogenesis.

Front 104

Pyruvate decarboxylase deficiency is characterized by high serum levels of what substances?

Back 104

Pyruvate decarboxylase deficiency is characterized by elevated levels of alanine, pyruvate, and ketoacids.

Front 105

The Tensilon test uses what drug to test for what disease?

Back 105

The Tensilon test uses the drug edrophonium (Tensilon) to diagnose Myasthenia Gravis.

Front 106

What is the mechanism by which the nicotinic acetylcholine receptors on muscle cells in the muscle motor end plates deliver their message?

Back 106

These receptors act as ligand-gated ion channels in order to deliver their message.

Front 107

Limb-girdle muscular dystrophy results from disorders involving what type of molecules?

Back 107

Disorders of extracellular matrix molecules such as proteogglycans can result in limb-girdle muscular dystrophy.

Front 108

Myotonic Dystrophy is the result of defects in what enzyme?

Back 108

Myotonic dystrophy results from congenital defects in a Dystrophic Myotonia Protein Kinase (DMPK).

Front 109

P/Q-type voltage gated calcium channels are defective in what syndrome?

Back 109

Lambert-Eaton Myasthenic Syndrome.

Front 110

Skeletal Muscle L-type channels are defective in what syndrome?

Back 110

Hypokelemic Periodic Paralysis.

Front 111

What molecules are responsible for the "arms" that link the pairs of subtubules that make up cilia? Lack of these arms is responsible for what disease?

Back 111

A pair of Dynein arms are attached to one of the subtubules in each pair and are responsible for acting as a motor to cause movemnt of the cilia. In Kartagener disease, the Dynein gene is mutated.

Front 112

Hepatosplenomegaly, dwarfism, skeletal abnormalities, mental retardation, and corneal clouding are all part of what syndrome? Name the enzyme deficiency associated with this disease.

Back 112

These signs and symptoms describe Hurler's syndrome. The enzyme deficiency that is seen in Hurler's syndrome is and Alpha-L-iduronidase deficiency.

Front 113

Beta-glucocerebrosidase deficiency is the enzyme associated with what disease? What are some of the associated signs and symptoms of this disease?

Back 113

Beta-glucocerebrosidase deficiency causes Gaucher's disease, which is characterized by hepatosplenomegaly and glucocerebroside accumulation in phagocytic cells.

Front 114

Hexosaminidase A deficiency is associated with what disease? What type of progression does this disease go through?

Back 114

Hexosaminidase A deficiency is associated with Tay-Sachs disease, which is characterized by progressive neurologic deterioration.

Front 115

Cystathione deficiency is also known as what disease?

Back 115

Homocystinuria.

Front 116

Homocystinuria (or Cystathione deficiency) leads to increased levels of what molecules in the blood? Why?

Back 116

Plasma Methionine and Homocysteine levels are elevated as a result of cystathionine synthase deficiency because this enzyme occurs in the pathways involving the metabolism of sulfur-containing amino acids and normally catalyzes the conversion of homocysteine to cystathione. When the enzyme is blocked, homocysteine (which is normally a degradation product of methionine) is remethylated by a salvage pathway resulting in the resynthesis of methionine.

Front 117

A patient with Homocysteinuria/Cystathione deficiency shows what signs and symptoms? Similar physical features of what other disease are present?

Back 117

A patient with homocysteinuria shows severe mental retardation as a child. Ocular lens dislocation is common, along with the sigmata of Marfan's syndrome such as tall stature for the patient's age, kyphosis, and a short trunk.

Front 118

What is the enzyme that catalyzes the the committed step of glycolysis? What is a key negative allosteric regulator of this enzyme?

Back 118

Phosphofructokinase I is the enzyme that catalyzes the committed step of glycolysis. When the citric acid cycle slows down, Citrate accumulates in the mitochondria, but it can move freely from the mitochondria into the cytosol. In the cytosol Citrate acts as a negative allosteric regulator of PFK-1.

Front 119

What key molecule in the parallel to the glycolytic pathway is a potent allosteric activator of PFK-1?

Back 119

Fructose-2,6-bisphosphate (which is normally broken down by Fructose-2,6-bisphosphatase-activated by cyclic AMP-dependent protein kinase) is a potent allosteric activator of PFK-1.

Front 120

What is the key molecule responsible for driving Glycolysis forward in response to hormonal regulation by Insulin and Glucagon. Explain the key enzymes involved and the intermediates produced.

Back 120

Insulin ramps up Glycolysis through stimulation of the enzyme PFK-2. PFK-2 produces Fructose 2,6-bisP from Fructose 6-P. Fructose 2,6-bisP is a potent allosteric activator of PFK-1. PFK-1 has the job of taking the majority of Fructose 6-P, which does not get used by PFK-2, and making Fructose 1,6-bisP, thus pushing Glycolysis forward.

Front 121

What are the three irreversible steps of Glycolysis?

Back 121

Hexokinase, PFK-1 (committed step), Pyruvate Kinase.

Front 122

What are the enzymes and steps that must be taken to circumvent the last irreversible step of glycolysis?

Back 122

The last irreversible step of glycolysis is the Pyruvate Kinase step, which converts PEP to Pyruvate. Thus, gluconeogenesis Pyruvate cannot obviously just be converted back into PEP. Therefore, 1) Pyruvate Carboxylase converts Pyruvate to Oxaloacetate, and 2) Oxaloacetate can be converted to PEP by PEP carboxykinase.

Front 123

What is Fructose 1,6 Bisphosphatase? What pathway is it a part of?

Back 123

Fructose-1,6-Bisphosphatase is the enzyme that splits Fructose-1,6-Bisphosphate back into Fructose-6-Phosphate and inorganic phosphate. This process is involved in Gluconeogenesis and is the reverse of the same step that is found in Glycolysis.

Front 124

What is Glucokinase? What other enzyme is it related to? What properties makes it special?

Back 124

Glucokinase is a liver enzyme that converts glucose in to glucose-6-phosphate, trapping it inside the cell. Glucokinase is does the equivalent job as Hexokinase in other cells. It is distinguished from Hexokinase because it is specific for glucose and is unresponsive to the negative feed back of Glucose-6-phosphate. Its function is to stor excess glucose, so it has a very high Km (i.e. low affinity) for glucose, becoming active only when the concentration of glucose is very high.

Front 125

What are the cofactors that Pyruvate Dehydrogenase requires to work?

Back 125

Thiamine, Pyrophosphate, Lipoamide, and FAD.

Front 126

What molecules are inhibitory to Pyruvate Kinase, the final irreversible step in glycolysis? What molecules are activatiors?

Back 126

Pyruvate Kinase is allosterically inhibited by ATP, Alanine, and Acetyl CoA. It is activated by Fructose-1,6-Bisphosphate.

Front 127

What cofactor does Pyruvate Carboxylase need to function?

Back 127

Biotin.

Front 128

What mechanism do alpha receptors work through? Briefly describe the pathway and the effects it has on intracellular Calcium levels.

Back 128

Alpha-1 receptors are coupled to Gq, which stimulates phospholipase C (PLC), leading to the hydrolysis of PIP2(4,5,), a phospholipid in the plasma membrane. PIP2 splits into two second messengers: IP3 (1,4,5) and Diacylglycerol. IP3 diffuses through internal storage sites, where it triggers the release of Calcium and increases the intracellular levels. Diacyglycerol remains in the membrane and activates protein kinase C.

Front 129

What is the 2nd messenger system used by the Alpha-2 receptors?

Back 129

Alpha-2 receptors are coupled to Gi, which inhibits adenylate cyclase, leading to decreases in intracelluar cAMP levels.

Front 130

Explain the 2nd Messenger system used by Beta receptors.

Back 130

All Beta receptors (both types 1 & 2) are coupled to Gs, which stimulates adenylate cyclase, leading to elevated intracellular cAMP levels.

Front 131

What is the enzyme that catalyzes the the committed step of glycolysis? What is a key negative allosteric regulator of this enzyme?

Back 131

Phosphofructokinase I is the enzyme that catalyzes the committed step of glycolysis. When the citric acid cycle slows down, Citrate accumulates in the mitochondria, but it can move freely from the mitochondria into the cytosol. In the cytosol Citrate acts as a negative allosteric regulator of PFK-1.

Front 132

What key molecule in the parallel to the glycolytic pathway is a potent allosteric activator of PFK-1?

Back 132

Fructose-2,6-bisphosphate (which is normally broken down by Fructose-2,6-bisphosphatase-activated by cyclic AMP-dependent protein kinase) is a potent allosteric activator of PFK-1.

Front 133

What is the key molecule responsible for driving Glycolysis forward in response to hormonal regulation by Insulin and Glucagon. Explain the key enzymes involved and the intermediates produced.

Back 133

Insulin ramps up Glycolysis through stimulation of the enzyme PFK-2. PFK-2 produces Fructose 2,6-bisP from Fructose 6-P. Fructose 2,6-bisP is a potent allosteric activator of PFK-1. PFK-1 has the job of taking the majority of Fructose 6-P, which does not get used by PFK-2, and making Fructose 1,6-bisP, thus pushing Glycolysis forward.

Front 134

What are the three irreversible steps of Glycolysis?

Back 134

Hexokinase, PFK-1 (committed step), Pyruvate Kinase.

Front 135

What are the enzymes and steps that must be taken to circumvent the last irreversible step of glycolysis?

Back 135

The last irreversible step of glycolysis is the Pyruvate Kinase step, which converts PEP to Pyruvate. Thus, gluconeogenesis Pyruvate cannot obviously just be converted back into PEP. Therefore, 1) Pyruvate Carboxylase converts Pyruvate to Oxaloacetate, and 2) Oxaloacetate can be converted to PEP by PEP carboxykinase.

Front 136

What is Fructose 1,6 Bisphosphatase? What pathway is it a part of?

Back 136

Fructose-1,6-Bisphosphatase is the enzyme that splits Fructose-1,6-Bisphosphate back into Fructose-6-Phosphate and inorganic phosphate. This process is involved in Gluconeogenesis and is the reverse of the same step that is found in Glycolysis.

Front 137

What is Glucokinase? What other enzyme is it related to? What properties makes it special?

Back 137

Glucokinase is a liver enzyme that converts glucose in to glucose-6-phosphate, trapping it inside the cell. Glucokinase is does the equivalent job as Hexokinase in other cells. It is distinguished from Hexokinase because it is specific for glucose and is unresponsive to the negative feed back of Glucose-6-phosphate. Its function is to stor excess glucose, so it has a very high Km (i.e. low affinity) for glucose, becoming active only when the concentration of glucose is very high.

Front 138

What are the cofactors that Pyruvate Dehydrogenase requires to work?

Back 138

Thiamine, Pyrophosphate, Lipoamide, and FAD.

Front 139

What molecules are inhibitory to Pyruvate Kinase, the final irreversible step in glycolysis? What molecules are activatiors?

Back 139

Pyruvate Kinase is allosterically inhibited by ATP, Alanine, and Acetyl CoA. It is activated by Fructose-1,6-Bisphosphate.

Front 140

What cofactor does Pyruvate Carboxylase need to function?

Back 140

Biotin.

Front 141

What is the most common cause of albinism? Describe the inheritance pattern that is associated. What diseases are albino patients predisposed to?

Back 141

The most common form of albinism is caused by a deficiency of copper-dependent tyrosinase (tyrosine hydroxylase), blocking the production of melanin from the aromatic amino acid tyrosine. This is inherited in an autosomal recessive manner. Patients are prone to develop sun-induced skin cancers, including both squamous cell carcinomas and melanomas.

Front 142

What is the signaling pathway that is stimulated by NO. Which second messenger is at work? Which protein kinase is activated? What are the receptors involved?

Back 142

The Guanylate Cyclase System is the signaling pathway involved with NO. The second messenger in this system is cGMP. cGMP activates Protein Kinase G. The receptors that are involved in initiating this pathway are ANP or NO receptors.

Front 143

Is Osteogenesis imperfecta a recessive or dominant disease? What is the main defect associated with this disease? What are the amino acids that are associated with this defect?

Back 143

OI is a rare genetic disorder that occurs in both recessive and dominant forms. The different types are all characterized by defects in the synthesis of type I collagen, which is highly enriched in Glycine and Proline. These defects produce an unstable collagen triple helix that is not as strong as normal collagen.

Front 144

Arginine and Ornithine are amino acids associated with which metabolic cycle?

Back 144

The Urea cycle.

Front 145

Which metabolic disease associated with amino acids and folate metabolism produce a phenotype in the patient that looks similar to Marfan syndrome, with the addition of mental retardation?

Back 145

Methionine and homocysteine maybe interconverted and are involved in folate metabolism. These amino acids are affected in diseases such as homocystinuria (mental retardation, osteoporosis, tall stature, kyphosis, and lens subluxation) or cystinuria (cystine kidney stones).

Front 146

What are the signs and symptoms associated with Phenylketonuria?

Back 146

Pale hair and skin, mental retardation if not treated early, and Musty smelling urine.

Front 147

Abnormal Tyrosine metabolism is associated with what diseases?

Back 147

Albinism (pale hair and skin, increased skin cancer), Cretinism (decreased T3 and T4), Tyrosinosis (liver and kidney disease), and Alkaptonuria (chronic arthritis and urine that turns black upon standing)

Front 148

Which amino acids are associated with diseases of branched chain amino acid metabolism (Maple-syrup urine disease)? What are the symptoms associated?

Back 148

Valine and isoleucine are the branched-chain amino acids involved in Maple-syrup urine disease. The accumulate and cause symptoms associated with central nervous system defects, mental retardation, and death.

Front 149

What is the abnormality, that is a heavy testing topic for the boards, that occurs to cause sickle cell anemia?

Back 149

A change of a Glutamic Acid residue to Valine at the sixth position of the B-Globin chain.

Front 150

Howell-Jolly bodies in a CBC are characteristic of what type of patient?

Back 150

The Howell-Jolly body is a little red dot that is seen in a a RBC on a peripheral blood smear. Patients that do not have a spleens are typically seen to have these present. This absence of a spleen can be due to surgical resection, or autosplenectomy associated with sickle cell anemia.

Front 151

Infection with what special virus will put Sickle Cell patients at risk for developing Aplastic Anemia?

Back 151

Infection with Parvovirus B19 will put sickle cell patients at risk for developing Aplastic Anemia.

Front 152

What is the therapy for Sickle Cell disease? Why does this therapy work?

Back 152

The therapy for Sickle Cell disease is to give the patient Hydroxyurea. This works due to the increased production of Fetal Hemoglobin (HbF) that Hydroxyurea produces.

Front 153

What is the job of the RER? It synthesizes proteins, but where do they go? What other organelle does it work in conjunction with?

Back 153

The RER functions to synthesize proteins destined for incorporation into the lysosomes and into membranes. Enzymes targeted to lysosomes in this way require post-translational modification in the Golgi apparatus.

Front 154

How does the Golgi work to target lysosomal enzymes to the lysosome? What disease is associated with a the defective enzyme that usually supplies this function? What is the name of this enzyme.

Back 154

The Golgi apparatus targets enzymes to the lysosome through addition of mannose-6-phosphate residues to the enzymes. A defect in activity of the enzyme Phosphotransferase causes I-cell disease (lysosomal storage disease)

Front 155

What is I-cell disease? What is the defective enzyme associated with this disease? Which cellular processes are intrerrupted?

Back 155

I-cell is a lysosomal storage disease and results due to defect Phosphotransferase enzyme. This disables the Golgi from targeting lysosomal enzymes for the lysosomes through mannose-6-phosphorylation. Thus, the lysosome cannot degrade the molecules that are sent to it.

Front 156

Where does the synthesis of enzymes destined for peroxisomes occur in the cell?

Back 156

The synthesis of Peroxosomal enzymes occurs on free polysomes.

Front 157

Where does the synthesis of triglycerides take place in the cell?

Back 157

The synthesis of triglycerides occurs in the Smooth Endoplasmic Reticulum.

Front 158

Which vitamin deficiency would most likely be the cause for Alopecia?

Back 158

Alopecia results from Biotin deficiency, which typically occurs from excessive consumption of raw eggs containing the biotin-binding protein, avidin.

Front 159

Dermatitis combined with dementia and diarrhea are components of what disease caused by which vitamin deficiency?

Back 159

Dermatitis, along with dementia and diarrhea, are components of Pellagra, which is caused by Niacin deficiency.

Front 160

What type of enzymatic reactions is Vitamin K involved in during the clotting cascade?

Back 160

Vitamin K is a necessary cofactor for gamma-carboxylation of glutamates in certain clotting factors: II, VII, IX, X, and proteins C and S.

Front 161

What is the intracelluar function of Actin?

Back 161

Actin are monomeric units that comprise cytoskeletal structural microfilaments.

Front 162

What is the function of Myosin?

Back 162

Myosin makes up microfilament proteins that are directed toward the (+) end of the filament.

Front 163

What is the function of Tubulin?

Back 163

Tubulin are monomeric units that comprise microtubules and are necessary for the movement of cargo throughout the cell.

Front 164

What is the function of Kinesin? Does it move cargo anterograde or retrograde?

Back 164

Kinesin are motor proteins that move cargo toward the (+) end of a microtubule, which is anterograde transport.

Front 165

What is the function of Dynein? Does it move cargo anterograde or retrograde?

Back 165

Dynein are motor proteins that move cargo toward the (-) end of the microtubule, which is retrograde transport.

Front 166

Ribozymes are designed to hybridize and catalyze sequence specific cleavage of RNA phosphodiester bondes due to secondary structures that they form. What form of RNA do they inhibit?

Back 166

MATURE mRNA.

Front 167

What type of symptoms does vitamin K deficiency produce in adults? What is it used for in newborns?

Back 167

In older individuals, vitamin K deficiency can lead to easy bruising, gum bleeding, and an increased prothrombin time. Newborns are given vitamin K at birth because there are no well developed gut flora to synthesize the vit K and it is needed to prevent rare cerebral hemorrhage of the newborn, as vitamin K is part of the coagulation cascade.

Front 168

When you hear about dermatitis, along with dementia and diarrhea, what vitamin deficiency should you think about?

Back 168

You think about Pellagra, and Niacin deficiency.

Front 169

Allopecia is due to what vitamin deficiency?

Back 169

Biotin.

Front 170

Vitamin K is a necessary cofactor for gamma carboxylation of glutamates in certain clotting factors. What are these clotting factors that it is associated with?

Back 170

Factors II, VII, IX, X and proteins C and S.

Front 171

Where is lipoprotein lipase found and what does it do?

Back 171

Lipoprotein lipase is located on endothelial cells, and is responsible for releasing triglycerides from the chylomicron core by hydrolyzing them to more easily absorbed fatty acids.

Front 172

What is the mode of inheritance of Glucose-6-phosphate dehydrogenase deficiency? What pathway is most affected by this disorder?

Back 172

G6PD is an X-linked recessive disorder that affects the Pentose Phosphate Pathway.

Front 173

Uric acid kidney stones are associated with Gout, which is classified as what type of disease?

Back 173

An inborn error of purine metabolism.

Front 174

Cholesterol gall stones are associated with what diseases?

Back 174

Diabetes Mellitus, obesity, pregnancy, birth control pills, and celiac disease.

Front 175

Struvite kidney stones are associated with what type of infection?

Back 175

Struvite stones are associated with infection by urea-splitting organisms such as Proteus.

Front 176

Describe the range of symptoms associated with Lead poisoning.

Back 176

Anorexia, apathy, aggressiveness, poor coordination, abdominal pain, constipation/diarreha, lead lines on gingiva and on epiphyses of long bones on X-ray, and wrist and foot drops.

Front 177

What are some of the inhibited enzymes and pathologies associated with Lead poisoning?

Back 177

Inhibition of Aminolevulinate (ALA) dehydratase and ferrochelatase occur in Lead poisoning and can result in microcytic, hypochromic anemia due to impaired heme synthesis. Inhibition of 5' nucleotidase produces basophilic stippling in erythrocytes due to retained RNA.